Tower of London

In modern times, Rudolf Hess, a war criminal, was a prisoner in the Tower.

An excerpt from the article 21 facts about Tower of London

In 1941, Hess, most likely voluntarily and without the Fuehrer's knowledge, flew a Messerschmitt Me 110E to Great Britain to negotiate the terms of German-British peace. Apart from working for the Nazi party, Hess's passion was aviation. He was an excellent pilot. In May 1941, he covered over 1300 km from Augsburg, Germany, to Scotland. He couldn't land at an airfield that was too small in southern Scotland, so he had to parachute. The British treated Hess as a prisoner of war. Winston Churchill refused to talk to him and had him locked up, first in the Tower of London and then in a guarded estate outside London.