Fort Saumarez
Guernsey
The 186th tallest tower in the world
Fort Saumarez is a Martello tower in Saint Peter (Saint Pierre du Bois), Guernsey, on a headland that forms the northern tip of L'Erée and extends to the Lihou causeway.
Building data from Wikidata (CC0); heights normalised. Summary from Wikipedia (CC BY-SA).