Brandenburg Gate, the Kremlin and St Basil's Cathedral were among the landmarks to go dark for Earth Hour on Saturday evening.
The global movement is held annually to encourage people to turn off their lights for 60 minutes as a symbol of their commitment to the planet.
It aims to spark a conversation about protecting nature not only to combat the climate crisis but to ensure our own health, happiness, prosperity and even survival, according to World Wildlife Fund Russia (WWF).
Beginning in Sydney in 2007, Earth Hour has spread to more than 180 countries, with tens of millions of people taking part.
