Hévíz–Balaton Airport (IATA: SOB, ICAO: LHSM) is an international airport located near Sármellék in Zala County, western Hungary. It serves the popular Lake Balaton resort region and the famous Hévíz thermal lake, one of the largest natural thermal lakes in the world. The airport was originally a military airfield during the Soviet era and was later converted for civilian use. It has operated seasonal charter and scheduled flights, primarily serving tourists from European markets during the summer season. Due to its regional nature and seasonal demand, the airport has experienced periods of reduced or suspended commercial operations, with activity largely dependent on charter operators and low-cost carriers serving holiday traffic to the Balaton region.