Aill na Cronain, Limestone cliff and climbing area in County Clare, Ireland

Aill na Cronain is a west-facing limestone crag in the Burren, County Clare, beside Aillwee Caves. Its centre is Skull Buttress, which looks like a skull from a distance; the flat Skull Slab VD climb sits on its nose. The East Side and Far East Side faces lie north of it, the Butterfly and Small Wall faces south. Most routes are short single-pitch climbs of 10–20 metres in the S to HS grades.

Climbers began documenting and developing routes at this site in the 1970s, with first recorded ascents occurring in 1971. The location has since grown into an established climbing destination in Ireland.

The crag's name means "Cronan's cliff" in Irish, and the central buttress is called Skull Buttress because it looks like a skull from a distance. Its "nose" holds the flat Skull Slab, a VD-grade climb that UKClimbing calls one of the best VDiffs in the country.

Reach the crag by a 10-minute walk north from the upper car park of the Aillwee Cave attraction. The cliff stands on private land, but climbing has been permitted since the early 1970s, so follow current access arrangements. Routes are short single-pitch lines of 10–20 metres, mostly in the S to HS grades.

The crag sits on private land in the townland of Ballycahill, yet climbing has been tolerated since the early 1970s. About 23 km southwest lies Ailladie, a limestone sea cliff holding some of Ireland's hardest climbs.