Devil’s hillfort - megalithic complex located on the bank of the Chertovskaya river near the town of Kozelsk in the Kaluga region, Russia. It's located in the national park Ugra. The main attraction of this place is a hill with outcrops of sandstone cliffs that are not typical for central Russia. Relict plants grow here, such as the moss Schistostega pennata (ака goblin gold, Dragon's gold, or luminescent moss), and the centipede fern.
Archaeological excavations showed that in the 3rd — 5th centuries there was a fortified settlement and pagan temple on this site.
The complex is considered a "place of power" and is often visited by esoteric, modern witches & sorcerers, followers of various religions and cults.