The Hammar Marshes (Arabic: هور الحمار‎) are a large wetland complex in southeastern Iraq that are part of the Mesopotamian Marshes in the Tigris–Euphrates river system. Historically, the Hammar Marshes extended up to 4,500 km2 (1,700 sq mi) during seasonal floods. They were destroyed during the 1990s by large-scale drainage, dam and dike construction projects. Since 2003, they are recovering following reflooding and destruction of dams.