About fifty kilometers northwest of Saint Petersburg and along the coast along the Gulf of Finland is Zelenogorsk. In 1939 Zelenogorsk was located on finnish territory and was called Terijoki and lay about twenty Kilometres from the Soviet border. When Soviet union attacked Finland on 30 November 1939, Terijoki was the first town to be conquered. Already in december that year, with Stalin’s approval, a finnish communist puppet government was installed. This new government was called Finnish democratic republic. The leader of the republic was the Finnish communist Otto Wille Kuusinen and it had its seat in one of the city’s mansions. The Republic was recognized only by the Soviet Union and had only nominal power without any influence whatsoever. In 1940, the Finnish government signed a peace treaty with the Soviet union, which automatically dissolved the temporarily republic.

Current status: Restored (2021).

Location: 60°11' 44.62" N 29°42' 01.27" E

Get there: Car.

My comment:

The Mansion was in disrepair for a long time but sometime around 2018–2019 the mansion was bought by a wealthy private individual who renovated it. To what extent the manor has been modified in connection with the renovation, I do not know.

Follow up in books: Trotter, R William: The Russo-Finnish Winter War of 1939-1940 (2010).