Buncrana [Bun Cranna - the mouth of the River Cranncha] is situated on the eastern shore of Lough Swilly, the deepest sea estuary in Europe. The settlement was founded in the 15th century around O'Doherty's Castle of which only the Keep remains. In the 18th century Buncrana was an English Garrison and was the location of Wolfe Tone's arrest during the 1798 Rising. The near-by Dún Rí Fort was built during the Napoleonic Wars and is now a military museum. In the 19th century Buncrana was a busy port and became a popular seaside resort in the 20th century.