The Maritsa Iztok Complex is the largest energy complex in South Eastern Europe. It is located in Stara Zagora Province, south-central Bulgaria. It consists of three lignite-fired thermal power stations. The complex is located in a large lignite coal basin, which includes several mines, enrichment plants, a briquette plant and its own railway system. The development of the thermal power and mining complex at Maritsa Iztok began in 1952, but the lignite deposits used to be known well in the mid-19th century.