Краснодар
Краснодар (pronounced "krasnodar") was the name of a mock Soviet town built in Caithness, Scotland some time before 1980. It was used to train soldiers during the time of the Cold War.
In 1980, the Twelfth Doctor, Alice O'Donnell and Mason Bennett travelled to Кpacнoдap in the TARDIS to try to solve the mystery of the ghosts of those killed by Fisher King. During their time in the town, they bumped into Albar Prentis, a Tivolian undertaker who was taking the Fisher King to his destination. When the Fisher King escaped, Prentis was murdered and became a ghost, which would go on to haunt the Drum in 2119.
The Doctor and the crew ran from the Fisher King. O'Donnell was unable to escape him and was also killed by him. She joined the group of ghosts in the future. Just before a face off with the Fisher King, the Doctor sent Bennett back to the base in the TARDIS while the Doctor sealed himself into the stasis chamber. He used one of the power cells from the hearse to cause an explosion, causing the destruction of the dam, which flooded the town. (TV: Before the Flood)
This new lake became the location for the underwater mining facility, the Drum. (TV: Under the Lake)
Behind the scenes
A real-life Краснодар (Krasnodar) exists in West Russia.