The Troitskaya Tower is a tower with a through-passage in the center of the northwestern wall of the Moscow Kremlin, which overlooks the Alexander Garden.
The Troitskaya Tower was built in 1495–1499 by an Italian architect Aloisio da Milano. The tower has borne several names, including Rizopolozhenskaya, Znamenskaya, and Karetnaya. It received its current name in 1658 from the Troitskaya Coaching Inn in the Kremlin. The two-story basement of the tower housed a prison in the 16th–17th centuries.
Wikipedia https://en.wikipedia.org/wiki/Troitskaya_Tower
Address (Unnamed Road), Москва 109012, Russia
Coordinates 55°45'8.211" N 37°36'52.325" E