Baths of Caracalla. The scale of the towering ruins of ancient Rome's most beautiful and luxurious public baths, the Baths of Caracalla, hints at their past splendor. Inaugurated by the emperor Caracalla in 217, the baths were used until the 6th century. An ancient version of a swank athletic club, the baths were open to all, though men and women used them separately; citizens could bathe, socialize, and exercise in huge pools and richly decorated halls. COST: EUR5.