Locally chosen, not algorithmic. In rough order of "if you only do one thing".
History
Kylemore Abbey
A neo-Gothic Victorian castle built in 1867 by Mitchell Henry as a gift to his wife Margaret. Run since 1920 by Benedictine nuns who fled their bombed monastery in Ypres. The Gothic chapel — a miniature cathedral by the lake — and the six-acre walled Victorian garden are the headlines.
Good to know · On the N59 between Letterfrack and Leenaun. Open daily. Shuttle bus to the gardens included.
Nature
Connemara National Park
Two thousand hectares around Diamond Hill at Letterfrack. The Diamond Hill loop is the must-do — a 7km waymarked walk to a 442m summit with the full sweep of the Twelve Bens, the coast, and Inishbofin offshore. Boardwalk for the lower section, stone steps higher up.
Good to know · Free park, free car park at Letterfrack. Visitor centre and café in season. Allow 3 hours for Diamond Hill.
Drive
Sky Road
An 11km loop west of Clifden, climbing high above Clifden Bay and looking out to Inishbofin. Two roads run parallel — the Upper Sky Road (the high one, with the views) and Lower Sky Road (along the shore). Drive the loop clockwise, finishing back into Clifden.
Good to know · Signposted from Clifden centre. Narrow but two-way. Several free pull-ins for photos.
Beach
Roundstone and Dog's Bay
Roundstone — Cloch na Rón — is a small fishing village on the south Connemara coast, with O'Dowd's pub on the harbour and the Roundstone bodhrán workshop (the makers of choice for serious players). Dog's Bay, two kilometres south, is a Caribbean-blue horseshoe of pure shell-sand.
Good to know · Free parking on the harbour and at Dog's Bay. No lifeguards.
Town
Clifden town
The 'capital of Connemara,' built between 1812 and 1830 by the D'Arcy family on a hill above the bay. Two main streets meet at the church spire. The Clifden Arts Festival in September and the Connemara Pony Show in August pack the town. Lowry's bar for sessions.
Good to know · Pay-and-display in the centre. Fuel and supermarkets all in town.
Drive
Doolough Valley
The R335 north of Leenane runs through one of the most haunting valleys in Ireland — a long narrow lake hemmed in by Mweelrea on one side and the Sheeffry Hills on the other, sheep on the road, almost no houses. A simple stone cross by the lake marks the 1849 Famine walk, when starving tenants were sent from Louisburgh to Delphi Lodge to be assessed for relief and many died on the road back. Treeless, treeless, and unforgettable.
Good to know · Drive it as the R335 loop: Leenane → Delphi → Doolough → Louisburgh, then return via Westport or back over the Sheeffry Pass to Killary. 30km of single-track tarmac, passing places, no fuel, patchy signal. The Famine memorial cross is a marked pull-in halfway up the lake.
View
The Twelve Bens
A compact range of twelve quartzite peaks at the heart of Connemara — Benbaun is the highest at 729m. Serious mountaineering territory; the casual visitor gets the best of them from the N59 between Recess and Maam Cross, or from Diamond Hill in the National Park.
Good to know · Don't attempt the high tops without proper gear and a forecast. The N59 viewpoints are free.