The Dun Laoghaire East lighthouse and dwelling was designed by Chief Engineer with the Ballast Board, George Halpin, with some later alterations by Jacob Owen. The light was established on 1st October 1847, 41 feet above high water, and of 12,000 candle-power. The tower was heightened by 12 feet, thus casting a beam on the Mugglin rocks off Dalkey for the first time. The lighthouse was fully automated on 31 October 1977.