Băile Herculane (Latin: Aqua Herculis; German: Herkulesbad; Hungarian: Herkulesfürdő; Czech: Herkulovy Lázně, Turkish: Lazarethane) is a spa town in Romanian Banat, in Caraș-Severin County, situated in the valley of the Cerna River, between the Mehedinți Mountains to the east and the Cerna Mountains to the west, elevation 168 m (551 ft).

The Romans established the town of Ad Aquas Herculis based on the legend that the weary Hercules stopped in the valley to bathe and rest.

It had an outer diameter of 47.4 m. The Austrian architects took the massive ruins into account in order to create a rectangular park with terraces which still exists today in the centre.

In modern times, the spa town has been visited for its supposedly natural healing properties: hot springs with sulfur, chlorine, sodium, calcium, magnesium and other minerals, as well as negatively ionized air.

New privately owned pensions and hotels appeared after 1989, along the Cerna/Tiena river banks, spread from the train station to the end of the hydroelectrical dam.