The Baths of Diocletian were a massive public bathing complex built in ancient Rome during the reign of Emperor Diocletian in the late 3rd century AD. Covering around 13 hectares, they were the largest of the Roman baths and could accommodate thousands of visitors. The complex included various facilities such as hot and cold baths, exercise areas, and gardens. Constructed using advanced engineering techniques, the baths featured intricate heating systems and impressive architectural designs. Today, parts of the structure still exist, and the site houses the Basilica di Santa Maria degli Angeli e dei Martiri, showcasing the enduring legacy of Roman engineering and culture.