North Stack North Stack North Stack (Welsh: Ynys Arw, meaning "rugged island") is a small island situated just off Holy Island on the north-west coast of Anglesey. North Stack can also refer to the headland opposite the island. This is the site of a redundant fog warning station, comprising a number of buildings, including the Trinity House Magazine, built in 1861, where shells for the warning cannon were stored. These buildings now house a bird watching observatory, giving a view of South Stack lighthouse across Gogarth Bay, and the studio of artist Philippa Jacobs. The Precambrian quartzite cliffs of this headland, including
Puffin Island (Anglesey) seals and bottlenose dolphins and harbour porpoises regularly visit the area. Pleasure cruises are also available from Easter to October to view the island, its seal colony and birdlife. There is one identified shipwreck, a steamship named "The Pioneer", which ran ashore in 1878 with a cargo of iron bars when the tow lines to it broke following its rescue from engine failure near the Skerries. Puffin Island (Anglesey) Puffin Island () (at or ) is an uninhabited island off the eastern tip of Anglesey, Wales. It was formerly known as Priestholm in English and Ynys Lannog in Welsh. A