Go down to Foilhommerum Bay, where the successful 1866 cable was landed

Find the cable station site at Knightstown and the story of the 1857, 1858 and 1865 failures

Work out what it meant that a message could suddenly cross the Atlantic in minutes

Visit the slate quarry at Dohilla that roofed the Houses of Parliament

In 1866 a cable was run from Foilhommerum Bay on Valentia to Heart's Content in Newfoundland, and this time it held. It took four attempts to get there: the 1857 try from Ballycarbery Strand failed, the cable landed at Knightstown in 1858 carried messages for about three weeks before it died, and the 1865 cable from Foilhommerum snapped in mid-ocean. Valentia went from a slate-quarrying island at the edge of Europe to one end of the first nervous system the world ever had.

Valentia: Where the Cable to America Landed

Iveragh and the Skelligs

Two weeks down the Atlantic edge: seven campsites, each with the challenges around it, from Croagh Patrick to the 618 steps of Skellig Michael.

The Wild Atlantic Way: Westport to the Skelligs

Book a licensed wildlife boat trip from Portmagee harbour that circles Puffin Island, a BirdWatch Ireland reserve where landing is discouraged in the breeding season to protect the breeding colony

Watch for grey seals hauled out on the rocks of Puffin Island and the Skellig channel, especially during pupping season, from mid-September through November

Keep to the operator's recommended distance from any hauled-out seal, and note how a pup's white natal coat differs from an adult grey seal's mottled grey coat

Walk Portmagee's pier and photograph the Portmagee–Valentia bridge, the crossing point many of these boat trips also pass under

Puffin Island, off Portmagee on the Iveragh Peninsula, is a BirdWatch Ireland reserve, acquired by its predecessor the Irish Wildbird Conservancy, and landing is discouraged in the breeding season to protect the seabirds — but grey seals haul out on the rocks around it year-round, with pups born from mid-September through November, most of them in October. Licensed boat trips circle the island from Portmagee harbour.

Puffin Island: Grey Seals off Portmagee

Find the Tetrapod Trackway on Valentia's northeast coast — footprints left by an early four-legged vertebrate 385 million years ago, among the oldest tracks of their kind anywhere

Go up to the slate quarry at Dohilla — a working quarry, so check access — which supplied slate for the Houses of Parliament and Westminster Abbey

Visit Valentia Island Lighthouse at Cromwell Point, guarding the northern entrance to Valentia Harbour

Cross the bridge from Portmagee, one of only two ways to reach Valentia along with the summer car ferry

About 385 million years ago something with four legs walked across wet mud on what is now the north-east coast of Valentia, and the prints set. They are among the oldest tracks of a land vertebrate found anywhere on Earth — the moment life came out of the water, recorded in stone you can stand beside. The island has a second seam of history in it: the slate quarry at Dohilla, opened in 1816, shut for most of the 20th century and worked again since the 1990s, supplied the roofs of the Houses of Parliament and Westminster Abbey. You reach Valentia by the bridge at Portmagee or, in summer, the car ferry.

385-Million-Year-Old Footprints on Valentia

Get out on a clear moonless night away from the village lights and let your eyes adapt for twenty minutes

Trace the Milky Way from horizon to horizon

Find one of the reserve's designated viewing points on the Skellig Ring

Learn why Gold Tier is the highest dark-sky grade there is, and what it takes to keep it

The Iveragh Peninsula between Kells and Caherdaniel holds Ireland's first International Dark Sky Reserve, and on 27 January 2014 the International Dark-Sky Association gave it Gold Tier — the first Gold Tier Reserve in the northern hemisphere and one of only four in the world. There is no town light bleeding in from anywhere, the Atlantic is on three sides, and on a clear moonless night the Milky Way is not a faint smudge but a structure you can trace from one horizon to the other.

The Kerry Dark Sky Reserve: Gold Tier on the Iveragh

Tour Skellig Six18 Distillery, named for the 618 steps on Skellig Michael

See the old RIC barracks and find out what happened here in 1867

Walk into the Cahergal and Leacanabuaile stone forts

See Ballycarbery Castle from the roadside viewing area

Find the O'Connell memorial facing his birthplace at Carhan

Cahersiveen, on the Ring of Kerry, is where the first shots of the Fenian Rising were fired in 1867, and its old Royal Irish Constabulary barracks of the 1870s, built in the Schloss style of its architect Enoch Trevor Owen, is now a heritage centre. The town's church is dedicated to Daniel O'Connell, with a memorial facing his birthplace at Carhan. Just outside the town are two stone forts close together, Cahergal and Leacanabuaile, and the ruin of Ballycarbery Castle, a 16th-century tower house. Skellig Six18, the distillery on the edge of the town, takes its name from the 618 steps up Skellig Michael.

Cahersiveen: Skellig Six18 and the Stone Forts

Walk the ruins of Ballinskelligs Priory by the shore

Walk out to Ballinskelligs Castle on its promontory, built by the MacCarthy Mór in the 16th century

Find out where the 1875 cable from Nova Scotia came ashore

Ballinskelligs — Baile an Sceilg, the town of the craggy rock — takes its name from the Skelligs off its coast, and it is in the Kerry Gaeltacht. By the shore stand the ruins of Ballinskelligs Priory, a house of Augustinian canons, and on a narrow, eroding promontory the MacCarthy Mór built Ballinskelligs Castle in the 16th century to guard the bay from pirates. In 1875 a transatlantic telegraph cable was brought ashore here from Tor Bay in Nova Scotia, 2,565 nautical miles away. Up the hill, the Cill Rialaig project keeps an artists' retreat in an old village.

Ballinskelligs: The Priory, the Castle and the Cable to America

Book and complete the boat trip to Skellig Michael from Portmagee or Ballinskelligs — landings are weather-dependent and cancelled more often than they run

Climb the 618 stone steps the monks cut, to the beehive huts of the early medieval monastery at the top

Find the filming locations used for Ahch-To in The Force Awakens and The Last Jedi

Look across to Little Skellig on the crossing, the largest gannet colony in Ireland and one of the largest in the world

Skellig Michael is a pyramid of rock eleven kilometres out in the Atlantic where monks built a beehive-hut monastery in the early medieval period and hauled every stone of 618 steps into place by hand. The Star Wars films put Luke Skywalker on those steps and the island has never been the same. Landings are capped, weather-dependent and cancelled more often than not, which is appropriate — the monks chose it precisely because it was hard to reach.

Skellig Michael: The Monastery That Became Ahch-To

Drive the hairpins of the Glengesh Pass south out of Ardara

Stop at the top of the pass and look back down the glen

Find a working handweaver in Ardara and watch Donegal tweed being made

Walk Maghera Strand and look into the sea caves under Slievetooey at low tide

Stop at the Assaranca waterfall on the road out to Maghera

Ardara is the weaving town of south-west Donegal, where Donegal tweed is still made by hand, and the road south out of it climbs the Glengesh Pass in a set of hairpins onto empty moorland before dropping away towards Glencolmcille. It is one of the great short drives in Ireland and it takes about ten minutes, which is the joke of it. West of the town, below Slievetooey, Maghera Strand hides more than twenty sea caves that you can only reach when the tide is out, and on the road out to it is the Assaranca waterfall.

Ardara and the Glengesh Pass

Walk right round the kerbstones of the mound — Dowth is free and unticketed, unlike Newgrange and Knowth

Find the crater left in the top of the mound by the 1847 excavation

Find the third entrance on the west side, an early Christian souterrain

Look for the quartz fallen outside the kerb, from the white facing the tomb once had

Stand outside at the winter solstice, when the alignment is on the setting sun rather than the rising one

Dowth is the third of the great Brú na Bóinne tombs and the one almost nobody visits — which is the reason to go. It has never been independently dated, but its features put it with the others, between roughly 3200 and 2900 BC. Quartz found fallen outside the kerb suggests it too was faced in glittering white stone. Dowth South, the shorter of its two passages, is aligned on the winter solstice sunset rather than sunrise, so the low light runs along the left side of the passage and lights three stones in the chamber. And on top there is a large crater, left by a botched Royal Irish Academy excavation in 1847 and never repaired.