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
Holy Island, Anglesey scientific interest – Beddmanarch–Cymyran. Holy Island is connected to Anglesey by two road links. The first, the Stanley Embankment, is made up of causeways carrying the A5/A55 and the main railway line to Chester and London, and the original bridge of the A5 post road. The second is Four Mile Bridge, which carries a 'B' road and is much smaller. The main settlement is the port of Holyhead, from which passenger ferries travel to Dublin Port, Ireland, and freight ferries also travel to Dublin. Holyhead railway station is located in the town. Other settlements include the villages of Trearddur Bay,