These illustrations show the Estonia mine site in Ida-Viru County, Estonia. It is the largest underground oil shale mine in Estonia and the world. It belongs to Enefit Power, an oil shale power and mining subsidiary of Eesti Energia (main Estonian power company). 

Mining started there in 1972. Oil shale is extracted at a depth of 50-60 metres and is made using modern technology.

In the future, when the mine will be closed, it is planned to generate electricity on the territory of the Estonia mine with the construction of a solar power plant and a pumped hydroelectric plant.