St Petersburg

St Petersburg, also known as Petrograd, was a city in Russia.

Sir Hamilton Seymour, the British ambassador to the Russian Empire during the Crimean War (1853-1856), was stationed in St Petersburg in 1854. (AUDIO: The Angel of Scutari)

In 1903, the First Doctor, Susan Foreman, Ian Chesterton and Barbara Wright left the unconscious Grigori Rasputin in the Summer Garden in St Petersburg. (AUDIO: The Wanderer)

In 1904, the Fifth Doctor, Tegan Jovanka and Turlough visited St Petersburg. Due to a teleportation accident, Tegan and Turlough were transported to Vladivostok, where they were forced to take a train back to St Petersburg. (PROSE: Gudok)

The Eighth Doctor claimed he took a train with Vladimir Lenin from Switzerland to Petrograd. (AUDIO: Storm Warning)

Behind the scenes
In real world, St Petersburg has also been known as Leningrad. However, no connection between the two names has been established in Doctor Who universe.