A natural axis of the Strakonice and Prácheň region, 113 km long, famous for gold mining and extraction of pearls from river pearl oysters. It is created by the confluence of Vydra and Křemelná at Čeňkova Pila in Šumava. The name is based on the Celtic word Atawa, which means “rich water”. The Podskalí educational trail goes along the river, which presents the natural and historical interesting facts concerning the river, among other things also the water-sportsmanship (rafting).