South Stack is one of the most spectacular locations on Ynys Mon [The Island of Anglesey]. The South Stack Lighthouse is built on Ynys Lawd, a small rocky islet about thirty metres off the edge of Holy Island, which itself is an island just barely separate from the main part of Anglesey.
The Lighthouse can be reached by a steep stone stairway of over 400 steps, and a bridge over the turbulent deep water channel, 100 feet below.
The Lighthouse has warned passing ships of the treacherous rocks below since its completion in 1809. The 28 m (91 ft) lighthouse was designed by Daniel Alexander and the main light is visible to passing vessels for 28 miles, and was designed to allow safe passage for ships on the treacherous sea route from Dublin, in Ireland, to Liverpool, in England.
South Stack is a popular visitor attraction, not only for the stunning views of the cliffs, coast and Lighthouse, but also for the surrounding nature reserve, run by the RSPB, with thousands of sea birds nesting on the cliffs in the Spring. The large granite cliffs rise sheer from the sea to a height of 60 metres.