Roman hypocaust system, Roman Baths Bath, UK

The remains of the Roman hypocaust system at the Baths in Bath, England, reveal one of antiquity’s most remarkable engineering feats. Here, rows of small brick pillars, called pilae, supported a raised floor, leaving a cavity beneath. Hot air and smoke from a furnace circulated through this space, radiating warmth upward and sometimes into hollow wall tiles, effectively turning the entire room into a heated chamber. Used to warm the caldarium and other bathing rooms, the hypocaust combined with Bath’s natural hot springs to create a luxurious and sophisticated spa experience. These ruins highlight Roman mastery of comfort and innovation.