Leningrad was a city in the Soviet Union.
History
During World War II, Leningrad was surrounded by the Wehrmacht. The curator of the Palace Museum fled with the collection of treasures to Siberia but he was unable to move the Amber Room. The Germans discovered the Room and transported it back to Germany. (PROSE: Cabinets of Curiosities [+]Mags L. Halliday, Collected Works (Big Finish Productions, 2006).)
Isabella Zemanova and her sons passed through Leningrad after escaping Stalingrad. (PROSE: The Beast of Stalingrad [+]Error: Code 2 - no data stored in variables, cache or SMW.)
Because KVI was afraid the Committee would detonate a time bomb in Leningrad and other places, they capitulated in the face of the enemy after only 32 minutes fighting. A KVI operative called it the shortest battle in human history. (AUDIO: Zone 10 [+]Error: Code 2 - no data stored in variables, cache or SMW.)
Behind the scenes
In real world, Leningrad is one of the names of St Petersburg. No connection between the two names has been established in DWU. Moreover, in the audio story The Night Witches, one of the Soviet pilots during World War II uses the name "St Petersburg" despite the city being called "Leningrad" in the real world since her birth.