If, when his reign came to an end in AD138, the Roman emperor Hadrian's villa had come up for sale, the estate agent's details would have been something to behold: 900 rooms, indoor and outdoor swimming pools, gyms, theatres, libraries and even underground parking for chariots, set in more than 120 hectares of landscaped gardens with elaborate waterworks and sculpture.
The villa, located near Tivoli, outside Rome, was one of the grandest private residences ever built. Even in ruins, it remains an inspiration for architects and others.
