Lake Balaton is a freshwater rift lake in the Transdanubian region of Hungary. It is the largest lake in Central Europe, and one of the region's foremost tourist destinations. The Zala River provides the largest inflow of water to the lake, and the canalized Sió is the only outflow.

Transdanubia is a traditional region of Hungary. It is also referred to as Hungarian Pannonia, or Pannonian Hungary.