The Celian Hill overlooks the Colosseum, and takes its name from Caelius Vibenna, the legendary hero of Rome's struggle against the Tarquins. In Imperial Rome this was a fashionable place to live, and some of its vanished splendour is still apparent in the vast ruins of the baths of Caracalla.
Today, thanks to the Archaeological Zone established at the turn of the 20th century, it is a peaceful area, a green wedge from the Aurelian Wall to the heart of the city. Through it runs the cobbled Via di Porta San Sebastiano, part of the old Via Appia. This road leads to Porta San Sebastiano, one of the best-preserved gates in the ancient city wall.
Completed by Emperor Caracalla in AD 217, the baths functioned for about 300 years, until the plumbing was destroyed by invading Goths. Over 1,600 bathers at a time could enjoy the facilities. A Roman bath was a serious business, beginning with a sort of Turkish bath, followed by a spell in the caldarium, a large hot room with pools of water to provide humidity.
Then came the lukewarm tepidarium, a visit to the large central meeting place, known as the frigidarium, and finally a plunge into the natatio, an open-air swimming pool. For the rich, this was followed by a rubdown with scented woollen cloth.
As well as the baths, there were spaces for exercise, libraries, art galleriesand gardens - a true leisure centre. Most of the rich marble decorations of the baths were removed by the Farnese family in the 16th century to adorn the interior of Palazzo Farnese.
Until recently, open-air operas were staged here - the vocal exertions of the performers are now thought to pose a threat to the structure of this ancient monument.