Fort Montgomery (Lake Champlain)

Fort Montgomery on Lake Champlain is the second of two United States forts built at the northernmost point of the United States part of the lake: a first, unnamed fort had been built on the same site in 1816 but had been disassembled after engineers realised they were building on Canadian territory. Following the realignment of the border in 1842, a second fortification named Fort Montgomery was built on the same site in 1844.

Source: Wikipedia — Fort Montgomery (Lake Champlain) (CC BY-SA 4.0)