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
Eagle Island lighthouses be seen to the east as far as Broadhaven Bay and to the south as far as Blacksod Bay. The lighthouses became operational in September 1835. Eagle Island is located close to the edge of the Continental Shelf and is constantly pounded by powerful waves from the Atlantic. When the lighthouses were first built in the 19th century there were two lighthouses and seven dwelling houses on Eagle Island, according to the 1841 census. By the 1911 census there was only one dwelling house listed on the island. Despite the erection of a massive storm wall to protect the lighthouses,