A ruined tower is most of what’s left of the monastery St Seiriol founded here in the sixth century on Puffin Island, known in Welsh as Ynys Seiriol, off Penmon Point at Anglesey’s eastern tip. Seiriol himself is said to be buried on the island, close to his mainland foundation at Penmon Priory. You can’t land, since the island is privately owned, but wildlife cruises from Beaumaris circle it from spring to autumn. Cormorants nest here in one of the largest colonies on the British coast, alongside razorbills, guillemots and grey seals. Puffins, which gave the island its English name, were nearly wiped out after rats came ashore from a wreck, and have only slowly recovered since a rat-clearance programme in the late 1990s.
