Of all the lighthouses in the world, none has been built further from the coast it illuminated than the one at the top of Bidston Hill, on the Irish Sea coast in England. This 100-acre hill is nestled in the wilderness and forests of the Wirral Peninsula and is one of the highest points on the Wirral, visible for miles around, especially from the sea.
The first pair of lighthouses rose here in 1763 to help ships navigate the shallow, sandy shores at the estuary of the Dee and Mersey Rivers as they approached the port of Liverpool. When one of the lower lighthouses collapsed a few years later, it was replaced by the new Bidston Hill lighthouse, almost four kilometers from the sea. Later, an even higher lighthouse was built here. These two lighthouses are also located 3.7 km apart, making them the farthest from any pair of lighthouses in the world.
Since Bidston Lighthouse was almost four kilometers from the sea, the captain of Liverpool Harbor, William Hutchinson, came up with a new method of lighting at night - a parabolic reflector. This was the first time such a reflector was used in a local lighthouse to concentrate a beam of light. The reflector was 3.5 meters in diameter and was probably the largest ever made for a lighthouse. This reflector was made of wood covered with small mirrors.
However, there were some problems with the reflector. The oil lamp consumed a lot of oil and produced a lot of smoke, which tended to darken the reflector. In the end, it was found that several smaller reflectors, arranged so that their beams were parallel, gave the same bright light and used less oil. The mechanism worked for over a century until the reflector was replaced by Fresnel lenses in 1873.
The lighthouses remained operational until changes in Liverpool Bay in the early 20th century made them unnecessary. The canal through which ships entered and exited the port of Liverpool was so silted that ships had to navigate a different route, rendering the lighthouses ineffective. Beadstone Lighthouse was extinguished in 1913.