Peter and Paul Fortress

Founded in 1703 to protect the fledging city of St. Petersburg from rampaging Swedes, the red walls of Peter and Paul Fortress were never needed for their original purpose. Instead the garrison was used as a jail for prisoners whose names read like a 'Who's Who' of Russia. Dostoevsky, Trotsky, Gorky, and even Lenin's bro, all did porridge here. Parts of the prison are now open to the public, although the main draw on the Fortress grounds is the splendidly-spired Peter and Paul's Cathedral. The tallest building in the city, the Cathedral is the final resting place of all the Tsars and Tsarinas, from Peter the Great through to Alexander III.

It really does smell like the elderly uncleansed! And some guy tried to convert me.

i think this was a terrible place to go. when i got there it smelt very bad like an old guy who hasn't showered in 3 days

Simply splendid. Don't come to St. Petersburg and miss the Peter and Paul Cathedral!