Poolbeg Lighthouse in Dublin Bay was built in 1768 and initially operated on candlepower (reputedly the first in the world to do so) but changed to oil in 1786. It was re-designed and re-built into its present form in 1820.
The lighthouse, one of a formation of three, is located on the Great South Wall (South Bull Wall), at the Port of Dublin, which extends from Ringsend nearly four miles out into Dublin Bay. The wall was the world's longest at the time of its building, and remains one of the longest sea-walls in Europe. One of the other two lighthouses is located on the Bull Wall opposite, and the other on a wooden platform mid-channel.
The Poolbeg Lighthouse is a handsome and conspicuous feature in the bay, in which it occupies an almost central position. It is nearly equidistant from Dublin, Dún Laoghaire, and Howth, and commands extensive views of the shores of the bay, with an unbroken panorama of the mountains on the south. Howth with its heather-clad hills, its bright green fields and rugged reaches of sea cliffs, looks particularly attractive from this point.