Boheh Stone – rock art and the rolling sun

The Boheh Stone (Irish: Cathaoir Phádraig, St Patrick’s Chair) carries the densest concentration of rock art known in Ireland – roughly 250 carvings on a single low outcrop, cut sometime between 3800 and 2000 BC. It sits on a grassy rise 6.4 km south-southwest of Westport in County Mayo, a National Monument owned by Mayo County Council, and the surface, flecked with quartz, has held its markings through several thousand Atlantic winters.

The carvings

The designs are mostly cup-and-ring motifs – circular hollows ringed by one or more concentric circles – with a smaller number of distinctive keyhole shapes. The stone keeps giving up more: in 2014 the archaeologist Michael Gibbons uncovered a previously hidden panel, and in 2023 Rónán Lynch proposed that the upper markings map the constellations Crux and Centaurus, star patterns visible from Ireland until around 4100 BC. Whether that reading holds or not, it points to a site that was watched and worked over a very long stretch of prehistory.

The rolling sun

The stone’s best-known feature is a trick of alignment with Croagh Patrick, off to the north-west. Twice a year – on 18 April and 24 August – the sun sets behind the mountain, and from the stone the disc appears to roll down its northern shoulder before it drops below the summit. The effect works because of the outcrop’s exact position and its elevation of 102 m, a fixed sightline that has not changed in thousands of years.

It was a local man, Gerry Bracken, who identified the phenomenon around 1990 after years of watching. The two dates fall either side of the growing season, which is part of why the alignment is thought to be deliberate rather than chance.

Pilgrimage and Christian legacy

The stone stands on the line of Tóchar Phádraig, the old pilgrim road from the western royal site of Rathcroghan in County Roscommon to Croagh Patrick. When Christianity reached the area, the existing sacred spot was renamed Cathaoir Phádraig and folded into the pilgrimage, so the same quiet hillside holds both prehistoric astronomy and medieval devotion.

Visiting

There is no gate, no admission and no set hours – the stone sits in a field open to walkers. A signposted entrance on the local Boheh road has room for a couple of cars, and a short footpath leads across to the outcrop. The ground is uneven and slopes toward the stone, so it is awkward for pushchairs or anyone with limited mobility, and there are no facilities of any kind. It is fully exposed, so bring waterproof footwear and a windproof layer, particularly in autumn and winter.

Getting there

• By car: from Westport, head south-southwest and follow the small signs to the monument off the local road; the parking is a signposted layby, not on the R335 itself.
• Public transport: Bus Éireann serves Westport; from there it’s a taxi or a guided walk that takes in the stone.
• On foot: the stone is a stop on the Westport-to-Croagh Patrick walking route.

Nearby

Westport, a short drive away, has the accommodation, cafés and restaurants. Westport House and the Great Western Greenway fill out a day, and the pilgrim village of Aughagower, a few kilometres on, sits on the same Tóchar Phádraig route with a pub or two.

Time your visit for a clear evening in mid-April or late August to catch the rolling sun, or come on a bright morning when the quartz in the rock throws the carvings into relief and the view runs unbroken across to Croagh Patrick.