Trwyn Du Lighthouse. Penmon, North Wales. Stood between Ynys Seiriol and Ynys Môn, the lighthouse marks the passage between the two islands and the north entrance to the Menai Strait. Built in 1838 by James Walker at the request of master shipmen at the port of Liverpool after the wreck of the Rothesay Castle ship in the adjacent waters, the stone tower is distinguished by its original three black bands painted on a white background. It bears the words "NO PASSAGE LANDWARD" on its north and south sides, and became the first 'Trinity House' lighthouse (the official authority for lighthouses in England, Wales, the Channel Islands and Gibraltar) to be automated when it was converted to unwatched acetylene operation. The lamp was converted to solar power in 1996 and has a 15,000 candela light that flashes once every 5 seconds which can be seen 22 km away. Additionally, a 178-kilogram fog bell sounds once every thirty seconds to warn vessels in cases of low visibility. It was originally manned by two keepers, but the tower has been unmanned since 1922 and is monitored and controlled from Trinity House’s Planning Centre in Harwich, Essex.