The Zala is a river in south-western Hungary. Its source is in the hills on the borders with Austria and Slovenia. Its length is 139 km and drains water from 2,622 square km. Several smaller rivers feed into it, including the Felső-Válicka, Szentmihályfalvai patak (brook), Szévíz csatorna (channel), Foglár csatorna on the right bank, and Szentjakabi patak, Sárviz patak, Széplaki patak, Csörgető patak and Nádas patak on the left bank. It flows through the city of Zalaegerszeg before flowing into Lake Balaton near Keszthely. The River Zala flows through the Hungarian counties of Vas and Zala.