added by archaeologs In Roman architecture, a bath complex with rooms of different temperatures and exercise areas. Such a complex of rooms designed for public bathing, relaxation, and social activity for the ancient Romans. The great imperial thermae are Baths of Titus (81 AD), Baths of Domitian (95), Trajan's Baths (c 100), Baths of Caracalla (217), and the Thermae of Diocletian (c 302).