The fastest-flowing river in the country originates near the village of Marosfő in Transylvania and empties into the Tisza below Szeged. Its Hungarian section is 48 km long, with the 18 km stretch between Nagylak and Apátfalva serving as a border river. It is a movable state border, meaning its riverbed is surveyed annually, and the state border is determined along the centerline of the navigable channel. This section contains many islands and sandbanks. The construction sand extracted from the riverbed is among the best quality, and its silt has been used as medicinal mud since 1961. Near Makó, its average discharge is 155 cubic meters per second.