A boardwalk and stone path run most of the way up Diamond Hill, which is why a 442m mountain with a genuine summit view ends up busier than almost any hill in Connemara – it’s reckoned the second most-walked trail in Ireland after Croagh Patrick. Don’t be put off by the word ‘hill’: it is a proper little mountain of pale quartzite, in Connemara National Park in County Galway, and after rain or in low sun the exposed rock on the north slope really does glint, which is how it got the English name. The Irish, Binn Ghuaire (‘Guaire’s peak’), remembers Guaire Aidne mac Colmáin, a 7th-century King of Connacht.
The path you climb exists because the mountain was loved nearly to death: it was closed from 2002 to 2005 after the old routes eroded badly, and reopened with the boardwalk and stone steps you walk on now.
Which trail
Everything starts and ends at the Visitor Centre. The one worth doing is the full upper loop to the summit – about 7km and two and a half hours, graded strenuous, with a stony quartzite ridge near the top that needs decent footwear and a steady head. If you only do one thing here, do the whole loop; turning back at the lower section means missing the entire point, which is the view from the top.
If the weather is genuinely bad, or you’re short on time or unsteady, the lower loop (about 2.8km, 45 minutes) is the honest fallback. It climbs across boggy ground on boardwalk, past glacial boulders, and gives you Kylemore Lough and Ballinakill Bay without the exposed ridge. There are also two short, flat options for families – the Ellis Wood nature trail and the Sruffaunboy trail – that loop through woodland and grazing at the base.
The view from the top
On a clear day the summit gives you the lot. Below to the north are the Gothic turrets of Kylemore Abbey and Kylemore Lough; east is the wall of the Twelve Bens; Tully Mountain stands over Ballinakill Bay to the north-west; and out west the Atlantic carries the islands of Inishbofin, Inishturk and Inishshark. The honest caveat: ‘on a clear day’ is the operative phrase. Connemara weather turns fast, and plenty of walkers reach the top to find the view packed away in cloud – though even then the bog and ridge have a moody quality of their own.
Bog, ponies and old farms
The boardwalk is there to keep boots off one of Ireland’s larger blanket bogs, where marsh orchids, lousewort and purple heather come and go with the season; you’ll hear meadow pipits, skylarks and stonechats, and you may see Connemara ponies on the lower grazing. The slopes hold the marks of older lives too: an abandoned 19th-century farm, and a megalithic tomb left by the first farmers here around 5,000 years ago. The park, opened in 1980, includes land from the old Kylemore Abbey estate, which the Benedictine nuns took on after fleeing Ypres in the First World War, and the Visitor Centre occupies farm buildings of the former Letterfrack Industrial School from around 1890.
Visiting
The Visitor Centre has free exhibitions on the park’s geology and bog, a café for afterwards, toilets, picnic benches and free trail maps; rangers run guided walks and talks in summer. (The children’s playground was closed for new equipment in mid-2026 – check before promising it to anyone small.)
Getting there
The park is signposted off the N59 just outside Letterfrack – about an hour and a quarter from Galway City, roughly three hours from Dublin. Without a car, Citylink runs from Galway via Clifden to Letterfrack, which gives you about three hours at the park – enough for the full loop at a steady pace – and there’s also a service from Westport. Check return times carefully.
Parking, dogs and weather
Parking at the centre is free but small, and it fills early on dry summer days; get there before 10am or leave it until mid-afternoon. Dogs are welcome on a lead. The summit is fully exposed and can feel several degrees colder than the car park, so carry waterproofs and warm layers whatever the forecast – and if it’s blowing hard or pouring, take the lower loop and save the ridge for another day.