State Museum of the History of St Petersburg.

Spread across the sprawling Petropavlovsk Fortress on Hare Island, this is less a single building and more a historic complex that serves as the city’s birthplace. Founded in 1703, the site grounds its vast collection within the original 18th-century military bastions and ramparts. The centerpiece is the Peter and Paul Cathedral, where the gilded 123-meter spire marks the burial vaults of the Romanov dynasty. Contrast comes in the Trubetskoy Bastion, a former political prison where visitors walk through preserved cells. The museum’s reach is surprisingly broad, housing everything from architectural ceramics and Art Nouveau design to a dedicated museum of Soviet rocketry. It functions as both a scholarly archive and a public park where locals sunbathe against the granite walls.