Bidston Lighthouse is the world’s most inland lighthouse.

By this I mean that of all the lighthouses in the world that were constructed as genuine navigational aids to mariners, none were built further from the body of water they lit than Bidston’s.

Liverpool’s Sea Lights were a pair of leading lights that guided ships through the Horse Channel. A line drawn from the upper light at Bidston through the lower light at Leasowe crosses the high water mark on Mockbeggar Wharf at a distance of 2.1 nautical miles (2.4 statute miles, or 3.9 kilometres). The distance between the upper and lower lights is 2 nautical miles (2.3 statute miles or 3.7 kilometres), also making the Sea Lights the furthest apart of any pair of leading lights in the world.

There are, of course, many lighthouses further from the sea than Bidston’s. They can be found on river banks, or canals, or lake shores, and have provided valuable service to mariners as navigational aids. But these were all built relatively close to the body of water that they lit.

I also rule out aerial lighthouses, such as the one at RAF Cranwell, in Lincolnshire. A few of these were built as navigational aids to pilots, not mariners, and they lit the sky, not the sea.

Some otherwise interesting “lighthouses” are disqualified on the grounds of not being genuine navigational aids to mariners.

During the 1920s, Benito Mussolini ordered the construction of a lighthouse atop his summer palace at Rocca delle Caminate, some 25 kilometres from the Adriatic Sea, and commanded the Italian Navy to include it in their list of operational lights. Flashing red, white and blue when Il Duco was in residence, it provided good service as a monument to the dictator’s vanity. Perhaps it helped the locals find their way home in the dark, but it was of no use to mariners as a navigational aid.

Cape Todd Lighthouse stands in the desert of central Australia, near Alice Springs, on the banks of the Todd River, which is usually dry. That doesn’t stop the Aussies from holding the annual Henley-on-Todd regatta, in which contestants bring their own bottomless boats and carry them at a run along the Todd River. They like to claim that the Lighthouse is a navigational aid, because it stops the contestants from running out of bounds during the race. Built by amateur radio enthusiasts, Cape Todd Lighthouse took part in the International Lighthouse and Lightship Weekend in 2013 and again in 2014, when it was listed as a “faux” lighthouse.

I stand by my claim until such time as someone provides evidence of a greater distance, or the Italian Navy blockades Liverpool in protest.

If you do know of any interesting inland lighthouses, please let us know by commenting on this post. We’d also like to hear about any claims for the most inland operational lighthouse, or for the most widely separated operational pairs of leading lights.

Further reading