Balaton (Plattensee), the largest lake of middle Europe, in the south-west of Hungary, situated between the counties of Veszprém, Zala and Somogy. Its length is 48 m., average breadth 3½ to 4½ m., greatest breadth 7½ m., least breadth a little less than 1 m. It covers 266 sq. m. and has an extreme depth of 149 ft. Its northern shores are bordered by the beautiful basaltic cones of the Bakony mountains, the volcanic soil of which produces grapes yielding excellent wine; the southern consist partly of a marshy plain, partly of downs. The most beautiful point of the lake is that where the peninsula of Tihany projects in the waters. An ancient church of the Benedictines is here situated on the top of a hill. In a tomb therein is buried Andrew I. (d. 1061), a king of the Hungarian Arpadian dynasty. The temperature of the lake varies greatly, in a manner resembling that of the sea, and many connect its origin with a sea of the Miocene period, the waters of which are said to have covered the Hungarian plain. About fifty streams flow into the lake, which drains into the Danube and is well stocked with fish. It often freezes in winter.

Lake Balaton is of growing importance as a bathing resort.