Hammat Gader is located in a small valley between the Sea of Galilee and Gadara to the east. Five hot springs flow through the valley and one of them (‘Ain al-Maqle, with water at 51°C) provides the bath with the mineral water that made it famous. The baths seem to be attested during the early Roman period (though not directly by name) and continue to be noted in the ancient sources through the Byzantine period. A number of dedicatory inscriptions were found in the bath indicating that it was renovated several times through the Umayyad period. It was apparently destroyed in earthquake of 749.
The excavation of Hammat Gadar began in 1932 with the discovery of a synagogue on Tell Bani in the valley. The Hebrew University of Jerusalem completed the excavations. That same year, E. L. Sukenik made a number of soundings in the bath and in the artificial mound that supported the theatre. The bath itself was not excavated until 1979 by Y. Hirschfeld and G. Solar, and the excavations lasted for seven seasons.
The bath covers an area of 5200 square meters and is built from the local basalt and finely cut limestone. The basalt stones are bound together by Roman cement, but the limestone is used without mortar. The floor of the bath is also built out of limestone.