The House of Amphitrite is the most celebrated of Bulla Regia's underground villas. You descend a staircase from ground level into a subterranean complex of rooms that were the cool, shaded private quarters of a wealthy Roman family, probably from the 2nd or 3rd century AD. The walls and floors are decorated with mosaics depicting marine scenes — Neptune, sea creatures, and mythological figures — that remain in remarkable condition.
The underground design was not a novelty or an eccentricity: it was a rational response to a climate where summer temperatures routinely exceed 40°C. The buried rooms stayed cool through the hottest months, making them habitable when the above-ground rooms were not. Walking through them, you get an unusually intimate sense of Roman domestic life — this was where the family actually lived, not a public space designed to impress.