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
Salt Island, Anglesey Salt Island, Anglesey Salt Island () is joined to Holy Island, Anglesey, in North Wales. It is a natural provider of shelter for the town's Old Harbour from the Irish Sea and is part of the Port of Holyhead. The island gained its name by a factory located on it which processed sea water in order to extract sea salt. By the early 18th century, the sea salt was often mixed with rock salt (often smuggled onto the island) to increase the quality of the factory's product. The factory ceased production in 1775. Another building no longer standing on the