Puffin Island — Ynys Seiriol in Welsh — sits in the Irish Sea off the easternmost tip of Anglesey, about four miles from Beaumaris pier. It is uninhabited, a privately owned Special Protection Area for seabirds, and reachable only by boat. Several operators run hour-long cruises from the Beaumaris pier in season, weather permitting.
The colony is large and noisy: razorbills, guillemots, kittiwakes, fulmars, shags, and cormorants nest on the cliffs, and Atlantic grey seals haul out on the rocks at the base. The puffins that gave the island its name are now reduced to a small population, but other species more than compensate. The ruins of a sixth-century monastery founded by St Seiriol are visible at the south end of the island.