Peter and Paul Fortress is the original citadel of St. Petersburg, Russia, founded by Czar Peter the Great in 1703 and built to Domenico Trezzini's designs from 1706 to 1740. Through the early 1920s, it was used as a prison and execution ground by the Bolshevik government. Since then, it has been adapted as the central and most important part of the State Museum of the History of St. Petersburg, which occupies most of the fortress building save the structure occupied by the Saint Petersburg Mint.