A hypocaust is an ancient Roman heating system used to warm buildings, particularly baths and villas. It consists of a raised floor supported by pillars, allowing hot air from a furnace to circulate beneath. This design effectively heats the floor and walls, providing a comfortable environment. The hypocaust system was an innovative engineering solution that showcased the advanced technology of the Roman Empire. It allowed for efficient heating, making public baths, such as those in Bath, England, popular social and recreational spaces in Roman society.