The hypocaust was an ancient Roman heating system used to warm buildings, particularly baths and villas. It worked by circulating hot air from a furnace through a series of empty spaces or flues beneath the floors and within the walls. This innovative design allowed for efficient heating, making indoor spaces comfortable during colder months. The system typically featured raised floors supported by pillars, creating a space for the hot air to flow. The Romans perfected the hypocaust, showcasing their engineering skills and understanding of thermal dynamics. This method of heating influenced later architectural designs in Europe and remains a significant aspect of Roman history.