The Maritsa River originates from the two Marichini Lakes, located in a deep cirque at an elevation of 2,378 meters above sea level between the peaks of Mancho, Marishki Chal, and the Twins in the Rila Mountains. The present-day Ibar River—which is believed to have retained the ancient hydronym Hebros—and the river originating from the Maritsa Lakes converge near the present-day village of Raduil.
The river flows through the regions of Sofia, Pazardzhik, Plovdiv, Stara Zagora, and Haskovo in southern Bulgaria. After leaving Bulgaria, the river flows successively through the northeastern part of Greece and the European part of Turkey. It empties into the northeastern part of the Black Sea.
Within Bulgaria, the Maritsa River has about one hundred major tributaries. They are distributed symmetrically; that is, the number of left-bank and right-bank tributaries is nearly equal. The fertile lands and the important transportation corridor provided by the Maritsa River valley have been a prerequisite for the formation of numerous settlements along its course since ancient times. There are a total of 52 settlements along the river, of which 12 towns and 22 villages are located in Bulgaria, 2 towns and 6 villages in Greece, and 3 towns and 7 villages in Turkey.
The Maritsa River boasts exceptionally rich biodiversity, with dozens of protected species of plants, fish, birds, and mammals. The river is a symbol of the city of Plovdiv and a favorite spot for sports and recreation for many, offering preserved nature and rich biodiversity within the urban environment. The Maritsa River is part of the Natura 2000 ecological network.
