The Sistan Basin is an inland endorheic basin (a basin where no water goes to the ocean or other lakes) in the southwest of Afghanistan and the southeast of Iran. It is one of the driest places in the world and an area where there are many long droughts. Its drainage basin is a river going from the mountains of Afghanistan into freshwater lakes and marshes and then to the salty Godzareh Depression. The Helmand River drains the basin's largest watershed. This river gets its water mostly from snow melting from the mountains of Hindu Kush, but other rivers bring water too.[1][2]