The major rivers in the country are the Danube and Tisza. About one-third of the total length of the Danube River lies in Hungary; the river also flows through parts of the Federal Republic of Germany (West Germany), Austria, Yugoslavia, and Romania. It is navigable within Hungary for 418 kilometers. The Tisza River is navigable for 444 kilometers in the country. Less important rivers include the Drava along the Yugoslav border, the Raba, the Azamos, the Sio, and the Ipoly along the Czechoslovak border. Hungary has three major lakes. Lake Balaton, the largest, is 78 kilometers long and from 3 to 14 kilometers wide, with an area of 592 square kilometers. Hungarians often refer to it as the Hungarian Sea. It is Central Europe's largest freshwater lake and an important recreation area. Its shallow waters offer good summer swimming, and in winter its frozen surface provides excellent opportunities for winter sports. Smaller bodies of water are Lake Velence (26 square kilometers) in Feher County and Lake Fertö (Neusiedlersee--about 82 square kilometers within Hungary).

Hungary has three major geographic regions: the Great Plain (Nagy Alfold), lying east of the Danube River; the Transdanube, a hilly region lying west of the Danube and extending to the foothills of the Alps; and the Northern Hills, which is Austrian a mountainous and hilly country beyond the northern boundary of the Great Plain.

The Great Plain contains the basin of the Tisza River and its branches. It encompasses more than half of the country's territory. Bordered by mountains on all sides, it has a variety of terrains, including regions of fertile soil, sandy areas, wastelands, and swampy areas. Hungarians have inhabited the Great Plain for at least a millennium. Here is found the puszta, a long, and uncultivated expanse (the most famous such area still in existence is the Hortobagy), with which much Hungarian folklore is associated. In earlier centuries, the Great Plain was unsuitable for farming because of frequent flooding. Instead, it was the home of massive herds of cattle and horses. In the last half of the nineteenth century, the government sponsored programs to control the riverways and expedite inland drainage in the Great Plain. With the danger of recurrent flooding largely eliminated, much of the land was placed under cultivation, and herding ceased to be a major contributor to the area's economy.