Caspian Sea
The Caspian has characteristics common to both seas and lakes. It is often listed as the world's largest lake, although it is not a freshwater lake. It contains about 3.5 times more water, by volume, than all five of North America's Great Lakes combined. The Caspian was once part of the Tethys Ocean, but became landlocked about 5.5 million years ago due to plate tectonics. The Volga River (about 80% of the inflow) and the Ural River discharge into the Caspian Sea, but it has no natural outflow other than by evaporation. Thus the Caspian ecosystem is a closed basin, with its own sea level history that is independent of the eustatic level of the world's oceans.
Shabran District
Greater part of the district is mountainous. The Caspian Sea is located in 12 km from Shabran city. The district borders upon Quba, Khachmaz, Shamakhi and Siazan Districts. Forests occupy 27000 ha in mountainous territories and plains near the Caspian Sea and they are of great importance with its climatic and natural resources for the district. The Shabran and Davachi Rivers flow through the district's territory, and the Valvalachay and Gilgilchay Rivers flow in northern and southern borders directly to the Caspian Sea. Samur-Davachi lowland has an altitude of −28 m below the world ocean level.