Zelenogorsk (Зеленогорск) is a town in the Kurortny district of the city of Saint Petersburg, in the Russian Federation.
During Tchaikovsky's lifetime it was known as Terijoki or Terioki (Териоки), and formed part of the Vyborg province (Выборгская губерния) of the Grand Duchy of Finland, within the Russian Empire.
Tchaikovsky in Terijoki
Tchaikovsky visited Terijoki as part of a six-day trip around the northern Baltic (from 26 July/7 August–1/13 August 1890). "I've been to Tsarskoye, to Peterhof, to Terijoki (Finland) with Menter, to Ozerki, and to Arkady, and generally spent a very pleasant time" .