Caldarium (hot baths), revealed during the excavation of Pompeii in the early 1800s, by Sir William Gell. A caldarium was a room with a hot plunge bath, used in a Roman bath complex. This was a very hot and steamy room heated by a hypocaust, an underfloor heating system. This was the hottest room in the sequence of bathing rooms. After the caldarium, bathers would progress through the tepidarium to the frigidarium.
Pompeii was an ancient Roman city near Naples in Italy. Pompeii was buried under ~6 m (20 ft) of ash by the volcanic eruption of Mount Vesuvius in 79 AD. Excavation of Pompeii revealed fascinating details about life in the ancient Roman empire.