St Sampson's Cathedral is the oldest church in St. Petersburg. It stands on the northern outskirts of the city and gives its name to Sampsonievsky Avenue. Rumor has it that it was in St. Sampson's Cathedral that Catherine II of Russia secretly married Grigory Potemkin in 1774.
The original wooden church was built in 1710 to honor Sampson the Hospitable. It was on the feast day of that saint that Peter the Great defeated Charles XII of Sweden in the Battle of Poltava. The existing church was built under Empress Anna to a design by Pietro Antonio Trezzini. It was consecrated in 1740. The tent-like belltower was built at a later date. The original church had only one dome; the four subsidiary domes were added in 1761.
Official website of the Saint Sampson's Cathedral http://eng.cathedral.ru/sampsonievskii_sobor/
Address Bol. Sampsoniyevskiy prospekt 41, 194044, St Petersburg, Russia
Coordinates 59°58'6.379" N 30°20'35.542" E