Ireland.
The most westerly country in Europe.
An outpost in the North Atlantic,
it is the final landfall for thousands of miles,
and towers above the sea.
You have the ocean, the sky, the light,
the wind even in your hair.
You couldn't be closer to nature than here.
Here, land and sea clash endlessly.
The rock of Ireland, bitten and scoured by glaciers,
is constantly being shaped and reshaped by water:
pounding waves below, and driving rain from above.
It's a very dynamic landscape.
It's very rugged.
It evolves day and daily.
From the rugged Antrim coast, to the Wild Atlantic Way,
this is Ireland.
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The Cliffs of Moher, a steep and sweeping precipice
on Ireland's jagged west coast.
The cliffs tower more than 700 feet above the stormy Atlantic
and present real danger to those that fail
to heed its warning signs.
In the year 2000, two experienced climbers died
and another was gravely injured when rocks above them gave way.
And in 2015, a visiting photographer
captured a spectacular rock fall in progress.
It won't be the last time that these stunning cliffs
crumble into the ocean, piece by piece.
A powerful reminder that the geological violence
that built Ireland is still very much alive here.
But despite their many rock falls,
the Cliffs of Moher aren't disappearing any time soon.
They have stood here, in one form or another,
for more than 300 million years, and greet visitors today
coming east across the Atlantic.
The Cliffs of Moher extend for five miles
along Ireland's Wild Atlantic Way:
a spectacular coastal route that winds
for nearly 1,600 miles from Derry in the north
to Cork in the south.
The Cliffs of Moher draw close to one million visitors
each year.
This is one of the country's most breathtaking panoramas.
The cliffs provide shelter for more than 30,000 birds
from 29 different species.
But the land on which they roost began to accumulate
long before birds had evolved.
Long before even their ancestors, the dinosaurs,
had appeared on the planet.
What you're looking at there is a cross section through time.
You can see how the sediments have changed from the base
right through the top.
You can see each successive layer.
The Cliffs Of Moher are the remains
of an ancient river delta.
Land created as flooded rivers dumped silt, sand, and mud
into a shallow tropical sea.
This sediment accumulated layer upon layer
for millions of years.
Those sediments are getting shallower and shallower
because more and more sediment is pouring out and building out
and making, essentially making land.
Each of those layers may represent one storm event
or one massive flood event.
The fine shale layers then represent longer periods of time
where sediment has collected more slowly over time
then the next flood event will come along.
New sediment deposited on top created crushing pressure
on the sediment layers below,
compacting them into the solid rock we see today.
Over millions of years, earth's shifting tectonic plates
carried these sediment deposits north
from their point of origin south of the equator.
But the story doesn't end there.
Repeating layers of sandstone, siltstone and shale
provide a clear view of an ancient sedimentary basin,
something usually found underwater.
Now above land, the Cliffs of Moher
reveal their history inch by inch.
This geological treasure has only been made visible
by the constant, clawing waves at the base of the cliffs.
Those waves come in, they will undercut the base of the cliffs,
especially the shaley bits that will weaken it.
And parts will fall into the sea.
The clear shale, those dark, very dark rocks
they've got fossils in them,
they've got bits of plant material,
they've got goniatites, but not much,
they don't have the same variety of fossils
that we get in the limestone.
So it was a very difficult environment
for things to live in.
You've got rivers flowing on a swampy, marshy area
and we get evidence of that from lots of tree material.
We even find the roots of those trees in some of the sections
so we know there was plants growing on essentially soil
in that area.
Just offshore, Branaunmore, a 220-foot-high sea stack,
stands like an ancient guardian.
The sea stack is a remnant actually
of where the cliffs used to be.
The Cliffs of Moher are eroding backwards.
Due to these joints, due to the shaley nature of the cliffs,
and mostly because of these fantastic waves that are
coming in from the Atlantic pounding it every year.
Those promontories can get isolated so either side of them
will get eroded away more and eventually they get eroded away
at the back.
And that, sometimes they'll form arches initially and then those
arches will collapse and be left with a sea stack.
The rate of recession for the Cliffs hasn't been measured.
But on the nearby Aran Islands the cliffs recede
more than a foot-and-a-half each year due to erosion
caused by battering waves.
The Branaunmore sea stack is a reminder
that nothing set in stone will remain forever.
By the waves it was created.
By the waves it will be consumed.
Over time that sea stack is going to be eroded
and that sea stack will fall and collapse into the sea as well.
They come and then they go.
There'll be new ones forming long after we're gone.
The Cliffs of Moher.
Not quite eternal, but immortalized in films
such as The Princess Bride
and Harry Potter and the Half-Blood Prince.
And no wonder:
they're a special effect 300 million years in the making.
Eight miles north of the Cliffs of Moher in the region known as
The Burren is the Ivy Cliff Cave, or as it's known today:
Doolin Cave.
Doolin Cave formed like every other cave in the Burren.
It's on the limestone, so there was groundwater,
there was water flowing,
slightly acidic water, and over time
that just eroded channels within the rock and the limestone.
Hidden 80 feet beneath the entrance to Doolin Cave
is its prized treasure: the Great Stalactite.
At 23 feet, it is one of the longest
free-hanging stalactites in the northern hemisphere.
Limestone stalactites form as slightly acidic rainwater
seeps through the bedrock, dissolving and eroding
the minerals as it flows.
Where water drips from the roof of a cave, dissolved limestone
in the water precipitates out and hardens as calcite.
Over time, minuscule amounts of calcite build up,
eventually forming giant solid deposits
that appear to drip from the cave ceiling.
In most caves you'll get single, small, straw-like stalactites.
They're quite common.
It started forming almost certainly in the same way
as all the others, but the water continued flowing there
for a longer period of time.
The Great Stalactite is a dramatic example
of the geological processes that shape Ireland.
It was created over hundreds of thousands of years,
literally one drip at a time.
But Doolin Cave and its remarkable stalactite
are just one small feature in the Burren landscape.
The Burren comes from the old Irish word bhoireann,
which means rocky place.
This rocky place, comprised of nearly 100 square miles
of spectacular, rolling hills,
was formed some 350 million years ago.
It is a limestone pavement: layer-upon-layer
of calcium carbonate sediment that was once at the
bottom of the ocean, deposited by the skeletal remains
of ancient marine organisms.
The sea life that formed this pavement once lived in the
same tropical sea, fed by the river that helped give rise
to the Cliffs of Moher.
The rock of the Burren was compressed and hardened
by the weight of successive layers of calcium carbonate.
This sea floor once occupied a place much farther south,
at the same latitude where Egypt is today.
As tectonic plates moved, these rocks drifted north,
landing here when an ancient ocean closed
and two plates of crust collided,
forcing what was the seafloor to emerge high above the waves.
In the south-eastern part of the Burren,
an arresting 560-foot-high limestone hill
bears the twists and bends of a landscape
that was once under extreme pressure.
It is Mullaghmore.
In Irish, it means Great Summit.
There's irregular curved folds in the limestone there
and that's a result of compression.
That's the result of a continent sliding along
the surface of the earth, hitting another continent,
the rocks buckle and they folded, nice and gentle.
But this was far from the end of the geological story
for this new piece of land.
What is now Ireland was subjected
to the unrelenting chill and crush of glaciers.
This area has been subject to glaciation.
Like most of Ireland it was covered by ice at some point.
And once the ice travelled mostly from the north, northeast,
it scraped off the surface, scraped off any soil
that was there, and it exposed bare limestone.
The last glacial period to affect the Burren
ended 14,000 years ago.
But while the landscape may have been scraped bare by ice,
the land itself is far from barren.
That then got colonized slowly afterwards by initially grasses
and then more advanced trees and bushes.
And then when humans came along, around about 5,000 years ago,
they started cutting those trees down.
The hunter-gatherers that cut down great swaths of forest
for timber also raised cattle that devoured grasses,
contributing to the current stark landscape.
In 1651 an English Army Officer described the Burren as:
"A country where there is not water enough to drown a man,
wood enough to hang one, nor earth enough to bury them.
And yet their cattle are very fat."
Wildflowers and grasses take root in cracks and crevices in
the limestone and flourish in the Burren's sweet, damp air.
It's got grasses, it's got shrubs, it's got a fantastic mix
of alpine and Mediterranean flowers.
People come from all over the world to see that together
in the same place, and it's not the Arctic and it's not
the Mediterranean: it's in the west coast of Ireland.
But underneath the surprising plant life
there's the limestone, scrubbed and scratched by ice,
stripped and depleted by man, and now eroded by water.
Once this limestone has been exposed to the surface
what happens is rain will fall on it,
and we get a significant amount of rain here in the Burren,
and that rain is very slightly acidic,
a natural acidity from the carbon dioxide in the air,
and when that hits the limestone it will start to dissolve it.
This process creates what is known as karst topography.
The limestone of The Burren
is laced with a network of fissures called grikes.
These fissures isolate blocks of stone
at the surface known as clints.
The irregular pits, the hollows, the curves, the grooves
they're all a result of water flowing onto the surface
and flowing maybe under the soil as well
where it dissolves even further.
As the limestone bedrock slowly breaks down,
grikes grow wider and deeper, more water flows through them,
and the grikes continue to grow larger.
There are these fractures or joints all through the limestone
here in the Burren, also out on the coast,
and on the coast they're wonderfully exposed.
They are exposed as lines of weakness in the limestone.
About 20 miles from Mullaghmore, the cracked Doolin coast
looks almost man-made with its precise, sharp lines.
But it, too, is a result of the tectonic and erosive forces
that shaped the rest of the Burren.
We've got the water dissolving the limestone
very gradually over a long period of time.
On the coast it's much more dynamic, it's much more active,
and every year you go back there
you see the coast looks different.
Cracks in the rock bear witness to the tremendous force
generated far below by the grinding of what are now
the North American and Eurasian continental plates.
This is two huge plates crashing against each other,
and when I say crashing that exaggerates a little bit.
This is a slow process.
A couple of centimeters a year these two continents
are pushing into each other.
But there's huge pressure behind that and this pressure
builds up, builds up in rock and eventually something will give.
Like miniature earthquakes, these rifts in the limestone
are the visible evidence of that tectonic pressure.
These might have been just like a millimeter, two millimeters
wide these cracks, they popped open right through
the whole Burren.
But even a mere fraction of an inch is enough for water
to exploit chinks in the limestone
as rolling Atlantic waves pummel the Doolin coast below.
These waves pack a huge punch.
They're coming right across the Atlantic.
And when it hits the rocks, especially at a high tide,
these joints, these cracks that we talked about,
are slightly open, the water whams against that.
It pushes in the air that's already in there
and it's like a pneumatic force pounding in against that rock.
And it can actually fracture the rock.
It'll fracture along lines of weakness already there.
That makes it more susceptible to be moved during that storm
or the next storm or subsequent storms.
The waves of the Atlantic are even powerful enough to move
entire blocks of limestone that have washed free from the shore.
The rocks are being in some cases flipped over
on top of each other, stacked up
into piles of large lumps of limestone by these waves,
and sometimes just dragged offshore and broken up.
It's a great way to look at
how the coast is actually eroding there.
While the west coast of Ireland offers dramatic cliffs
from which to gaze out over the tempestuous Atlantic Ocean,
the east coast rewards visitors with panoramic views of peaks
and glens steeped in rich history:
the Wicklow Mountains.
This is the largest area of continuous high ground
in Ireland: nearly 200 square miles
with an unbroken elevation of more than one thousand feet.
The entire region is the result of what's known as
an igneous intrusion: a massive geological event
that occurred about 400 million years ago.
The continental plates of North America and Europe collided,
generating tremendous heat that melted the rock,
which then rose as magma.
But without the fiery force of a volcano, the magma slowly cooled
without breaching the surface, creating a form of igneous rock
familiar to us all: granite.
This mass of granite forms the Leinster mountain chain,
the largest continuous area of granite in Ireland and Britain.
For centuries, man has quarried granite
from the Wicklow Mountains, but it's not the only product
of these beautiful hills and valleys.
As the rocks were subjected to intense heat and pressure,
they were effectively cooked,
changing form into what's known as metamorphic rock.
These rocks contain elements
such as lead and zinc, copper and silver.
They were concentrated into thin narrow veins of mineral ore.
They filled those cracks in the rock and concentrated
in specific kind of fractures so they then became a target
for miners in the 1800s.
They were a place where you could go in and you could
dig in a narrow tunnel to extract the lead ore.
It was a mining center of great importance in the 1800s.
For more than 150 years,
the Wicklow mountains were mined for their treasures.
There was even a brief gold rush in the 18th century
after nearly 200 pounds of gold were discovered here.
Today, the lead mines, closed for good in the mid-1950s,
sit abandoned in the Glendalough and Glendasan Valleys.
But long before miners began their excavations,
glaciers left their mark on the Wicklow Mountains.
During the Ice Age, layers of snow and ice accumulated,
growing heavier with each year.
Over time, the glacier slid down the mountainside,
carving out massive hollows and valleys between the peaks.
The glacier came down and scooped the rock
out of this valley and deepened it,
and then after all the ice melted away
the over-deepened valley was filled with water
and that's what's here now.
At the heart of the Wicklow Mountains is Glendalough:
the valley of two lakes.
Glendalough stretches for nearly two miles and is
one of Ireland's most popular tourist destinations.
It is an area of sublime natural beauty
and fascinating history: from miners and monks, to monsters.
The sixth-century monk St. Kevin is said to have
banished a monster from one of the lakes at Glendalough
after it harassed the locals and their livestock.
Upper Glendalough is a magnificent example
of a glacial ribbon lake, a long and narrow body of water
usually found in a trough formed by a glacier.
A normal river valley is a kind of a V-shape
but a glacial U-shaped valley is sculpted by ice
in a glacier going down and, as you can see behind us,
it's got steep sides, steep cliffs there,
and the valley floor is relatively flat.
To maintain water levels at Glendalough,
these glacial basins need to be fed,
and no glaciers remain today.
Mountain streams and rivers now feed these lakes
and provide drinking water for nearby towns.
The River Liffey, which runs through the center of Dublin
more than 50 miles away, begins its journey here
at the Liffey Head Bog.
Lots of rain, combined with poor soil drainage
provides the ideal environment for Wicklow's
signature ecosystem: the Blanket Bog.
A blanket bog is what coats the mountain plateau here.
It's a kind of plant structure
that's growing in a waterlogged soil on top of the rock.
Moss grows in that and it forms this layer a meter or two thick
over the upland areas and it's a very
specific kind of plant community.
The blanket bog, and the moss that dominates it,
draw nutrients from rainfall to create an environment
that's highly acidic, poor in nutrients and low in oxygen.
Only certain plants can tolerate such a hostile setting,
making the blanket bog a highly specialized ecosystem.
As as the sort of living layer keeps growing up,
the bottom bits die away.
But because they're waterlogged, they form this layer of peat
which is a low-energy carbon fuel.
And people used to dig that in the past.
If you're on those upland areas, you see these sort of trenches
where people have extracted peat.
For centuries, people in the mountains cut peat for fuel
to warm their houses.
Today, just 28 percent of Ireland's original blanket bog
remains intact.
But now it's protected because it's an ecological community
that's very well represented in Ireland.
It's important to maintain because it's plant
and ecological diversity that you don't see in other, say,
upland areas in Europe.
Peat grows just a fraction of an inch per year
and can reach down for several yards.
The partially decomposed plant matter that forms a peat bog
can take thousands of years to accumulate.
It's a slow process, like the movement of tectonic plates,
the crush of glaciers,
and the building of a bridge to Scotland.
According to Irish legend, the amazing rock formations at the
Giant's Causeway on Northern Ireland's Antrim coast
are the remains of a bridge built by the giant Finn McCool.
He built it for a showdown with his rival,
an oversized Scottish rogue named Benandonner
who lived across the North Channel in Scotland.
Or so some would have you believe.
The Giant's Causeway is more than rocks.
I have listened to stories about a giant called Finn McCool
all my life.
And I've been working here for 30 years.
I've been sharing them stories with visitors
virtually all my life.
It's easy to imagine why early inhabitants would credit
a mythic giant with the creation of this extraordinary setting.
But the 40,000 interlocking basalt columns
of the Giant's Causeway were actually formed
by a volcanic event more than 50 million years ago.
Deep below the surface, shifting tectonic plates
forced massive volumes of molten rock through fissures
in the surface to create layers of basalt rock.
Wind, rain and waves carved a valley.
More volcanic eruptions followed.
Lava flowed quickly in thick streams.
The valley filled up with lava until it was 100 meters deep.
It was 1,200 degrees Celsius.
And it's like everything.
If you boil a kettle it will cool down.
The pool of lava had to cool down.
Lava at the bottom of the valley cooled slowly.
Then, like mud in a shallow pond on a hot day,
as the lava cooled it contracted and cracked in even patterns.
During the Ice Age,
glaciers scraped away at the top layers of rock.
When the ice retreated, sea levels rose,
and pounding waves wore away at more rock.
Variations in the rate of cooling
produced the honeycomb-like monument that stands today.
Columns can reach 39 feet tall.
While the solid lava deposits in the cliffs
measure more than 90 feet thick.
High seas pound the rocks of the Giant's Causeway.
Ireland is known for its volatile weather,
and here on the north-east coast,
sea mist can roll in quickly.
Navigation can be treacherous,
and ships need to steer clear of the rocks.
The coastline that surrounds Giant's Causeway
has caused many wrecks.
In 1588, more than 1,000 seamen died when a
Spanish military ship loaded with treasures sank here.
Today, these formations
also go by the name Spaniard Rock.
There are many versions of the legend of the Giant's Causeway.
Some say Finn destroyed the bridge he built.
Others say the Scottish giant destroyed it.
But no one disputes why the legend arose in the first place.
Eighty miles across the North Channel,
on the Scottish island of Staffa,
there are basalt columns
identical to those found on the Giant's Causeway.
The columns at Staffa are part of the same lava field
that built the Giant's Causeway,
and have fueled its long-standing legend.
The Giant's Causeway has been a tourist draw for 300 years.
More than half a million people visit each year.
It is the by far the most popular tourist attraction
in Northern Ireland.
Geological studies here have contributed greatly
to our understanding of basaltic volcanism.
In 1986, the Causeway was declared
a UNESCO World Heritage site.
Today it's owned and managed by the National Trust in the UK,
to protect this iconic segment of Irish heritage
for future generations.
When this site was actually privately owned,
the site was quarried.
There was a serious lot of stones took off it.
The National Trust bought the site.
When they bought the site all that stopped.
You know, no more stones left the site.
A good thing, too.
No one wants a giant at their door
looking for his stolen rocks.
Some rocks near the Causeway, carved by millions of years
of erosion, resemble elements of Finn McCool's world:
the Chimney Stacks,
the Organ,
and the Giant's Boot.
The Boot is one of the most popular features
on the Causeway.
Based on the size of the boot, it's estimated that Finn
would have been more than 50 feet tall.
It's a boot.
You know, it's the shape of a boot.
I believe it's a boot.
I believe the giant Finn McCool left it there
for us to have a look at.
It's a size 93 and a half.
A geologist would totally disagree with you.
The same period of extreme volcanic activity
that created the Giant's Causeway also gave rise
to Slieve Gullion 100 miles to the south.
Slieve Gullion is known as the most mysterious mountain
in Ireland.
And it's got lots of myths and legends associated with it.
And it's the eroded heart of a volcano.
More than 60 million years ago, volcanic turmoil far beneath
the surface caused the original Slieve Gullion volcano
to collapse into a great chamber far below.
The magma in this chamber
slowly cooled to form the solid granite seen today.
Surrounding the volcano was a circular fracture in the rocks,
seven miles in diameter.
Magma rose through this crack and cooled,
forming what's known as a ring dyke,
leaving a circle of hills around Slieve Gullion,
known today as the Ring of Gullion.
The landscape here has been designated
as an Area of Outstanding Natural Beauty,
and is home to a vibrant floral community.
Slieve Gullion is designated as a special area of conservation.
This heather is very, very special.
We've got ling heather and bell heather.
You can still see the lovely purple shades up the mountain.
Tales of the Irish giant Finn McCool
dwell in Slieve Gullion as well.
The landscape has ignited the imaginations
of settlers old and new.
People here living nowadays, they draw inspiration
from the mountain and those myths and legends
and those characters in their past.
On a day like today whenever we do have that low-lying mist,
it's fantastic because we can see the peaks of the ring dyke
peeking through all that mist.
You can just imagine whenever those myths and legends
and those characters in the past were roaming around here
and it's very easy to see why this is one of the most
mystical mountains in Ireland.
The legend of Finn McCool extends from Slieve Gullion
in the east, all the way west to the Slieve League Cliffs.
At the base of the cliffs,
in the Grey Mountains of County Donegal,
two sea stacks - the Giant's Desk and Chair -
are said to be where Finn McCool
drew up his plans for the Giant's Causeway.
But there's more here than the office furniture
of an angry giant.
The big significance here I suppose
is the sheer size in the landscape.
So it's notable from the sea, so early mariners,
people coming to Ireland over the times, would've seen it.
It would've been a landmark for them.
The majestic cliffs of Slieve League
rise nearly 2,000 feet above the ocean.
They are the highest sea cliffs in Ireland,
twice as tall as the more famous Cliffs of Moher.
Their origins are just as remarkable.
About 200 million years ago, ourselves and the Appalachians
were all the one mountain system way down south of the equator
and over time the whole system moved up north
and divided apart.
Slieve League has been recognized as the official
landfall for the International Appalachian Trail.
These mountains are the trans-Atlantic,
geologic extension of North America's
Appalachian Mountains.
The rock here has been directly linked
to that on the east coast of Canada.
Our nearest neighbor in those times
would've been Newfoundland.
So you can see where the Irish connection
was in Newfoundland even way before the people were there.
The crashing waves below seem quiet from so high above.
And although Slieve League's steep face plunges straight into
the powerful Atlantic, erosion by waves has played
only a minor role in shaping this part of the coast.
Slieve League was carved not by water, but by glaciers.
This whole area here would've been under ice
maybe 70 to 100 meters deep and the ice has ground out
and very much shaped the cliffs.
We had thousands of years of ice here up until about
10,000 years ago at the end of the last ice age.
But right behind me here down in the cove there
with the Giant's Desk and Chair,
was a glacier there for thousands of years.
Research suggests that the ice sheet that covered Slieve League
may have been nearly half a mile thick.
Deep enough to encase the summit.
The enormous weight of that volume of ice would have
depressed the Earth's surface by as much as 650 feet.
Slieve League's dizzying slopes rise to the ridges and trails
used by hikers to traverse this natural wonder.
Leading to the summit is a trail known as One Man's Pass.
It is an arete, a knife-like ridge of rock
formed when two glaciers erode parallel, opposing valleys.
It offers breathtaking views for hikers with good balance
and nerves of steel.
Most people can cross the One Man's Pass.
But it's a section of the trail that's about a half mile long
that's only two foot wide.
You've a drop down to the ocean of over 1800 feet.
I always lean the other way,
it's only 1400 feet down to a wee lake.
Some people will crawl it, some people will walk it,
some people will pray on it.
The otherworldly majesty of Slieve League
has drawn and inspired giants and mere mortals alike
over hundreds if not thousands of years.
Some seek to connect with a higher power.
There's a Christian pilgrimage going on here
for almost 2000 years,
since the early Christian monks settled up here.
And these pilgrimages we know go back pre-Christian
and archaeological evidence will show us
that there was people living, or doing things
on these mountains way before Christianity.
The cliffs are also home to military installations built
to watch over the possible trespasses of a French Emperor.
These signal towers, the British built them here
from 1803 until about 1806 or 1807.
And they built a whole series of these
right around the coast of Ireland.
They were watching out for Napoleon.
The British were afraid he would invade Ireland, arm the Irish,
and then maybe chase them out and invade Britain.
So this system was set up -
an early watch system basically is what they are.
And they're still standing today.
Shaped by glaciers, the cliffs of Slieve League
are a breathtaking example of Ireland's natural beauty.
You couldn't be closer to nature than here.
You have the ocean, the sky, the light,
the wind even in your hair.
You can just get lost in nature.
You couldn't be in a better place.
Ireland: small in size, but epic in wonder.
Its vistas and wild spaces are fit for ancient, mythical heroes
and 21st-century explorers.
It is surrounded by the sea,
yet tied to other lands far across the ocean.
Here, rock and water are locked in constant struggle,
keeping the Earth in a state of flux,
ensuring that nothing is set in stone forever.
Ireland's mountains and cliffs, its valleys and lakes,
will continue to rise and fall with the passage of time
on a scale far beyond the realm of mere mortals.
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