Roundabouts in tunnels, and other bathing essentials

Forgotten tunnels under the Caracalla baths in Rome give insights into the empire

In the middle of a patch of grass amid the ruins of the Caracalla baths, in Rome, is a staircase that leads deep into the ground to a world resembling the lair of a James Bond villain.

“This is our glimpse at maniacal Roman perfection, at incredible hydraulic technology,” says archaeologist Marina Piranomonte, as she descends and indicates a network of tunnels, each measuring six metres high and six metres wide, snaking off into the darkness.

The baths, on a sprawling site slightly off the beaten track in a city full of monumental attractions, hold their own against the nearby Circus Maximus, its shattered walls standing 37 metres high, and recalls the heyday of the complex in the second century when 5,000 people bathed there every day.

But for Piranomonte, the 3km-long triple-tiered grid of tunnels under the site, of which the first tract will open to visitors this month, really shows how seriously the Romans took their sauna time.

An army of hundreds of slaves, who were kept out of the sight of bathers, scurried along the tunnels feeding 50 ovens with tonnes of wood a day. These heated the water that surged through a network of underground channels that came, via aqueduct, from a source 100km away. Below that, massive sewers, which are now being explored by speleologists, flowed towards the Tiber.

“It’s the dimension and the organisation that amaze. There is no spa as big as this anywhere in the world today,” says Piranomonte.

Upstairs, Romans would kick off a visit with a session in one of two gyms, then enjoy a sauna and a spell in a hot tub in the 36m-wide, domed caldarium, which is slightly smaller than the Pantheon in Rome. The tepidarium then beckoned before a cool-down in the frigidarium, a space so elegant that its design and dimensions were copied at Union Station in Chicago.

“The side room at the station where the shoot-out on the stairs is set in The Untouchables actually contained a large cold bath here,” says Piranomonte.

A 50m pool and a garden with a lending library flanked the baths. “The emperor Caracalla was cruel, but he built beautiful things,” says Piranomonte, who is in charge of the upkeep of the site.

A thousand years after they were built, the ghostly ruins of the massive buildings were overgrown and abandoned. “Because it was on the outskirts of Rome, no one built on top of it and the tunnels were simply forgotten, probably sealed by undergrowth,” she says.

Following their rediscovery at the end of the 19th century, Mussolini strengthened the tunnels when he decided to stage operas amid the ruins overhead, but Piranomonte is less than impressed with his handiwork.

“Look at the rainwater trickling through; that’s Mussolini’s bricks leaking, while ours are fine,” she says, pointing to the perfect Roman brick arches disappearing into the gloom.

The reopening of a short stretch of the tunnels on Friday will complete a clean-up of the baths. The opera, which used the remains of the caldarium for a stage and kept a stage-set workshop in one of the saunas, has been moved back into the gardens.

A €450,000 restoration programme also saw the reopening this month of an underground temple linked to the tunnel network at the baths. It was dedicated to Mithras, the deity whose popularity soared just before Christianity took hold in the Roman empire.

Entering the temple, which boasts black-and-white floor mosaic and is the biggest of its kind in the Roman empire, Piranomonte points to a frieze of Mithras holding a globe but missing his head. “Probably taken off by the Christians,” she says.

A chamber flanked by a banqueting area centres on a large pit where a drugged bull was placed on a metal grille and butchered. Below the grille is a small niche where an initiate to the cult would crawl to be drenched in bull’s blood. “It was a cruel cult, for men only, so you understand why Christianity got the upper hand,” says Piranomonte.

Emerging from the temple, the archaeologist turns left and pauses before what she describes as her favourite part of the baths: an authentic Roman roundabout. A large arch leads to the entrance of the tunnel network, where carts carrying tonnes of logs would queue to enter to feed the ovens. Fully excavated and restored, the tunnel starts with a roundabout where there is a kiosk for a guard to stop traffic jams. “A Roman spa with a roundabout,” says Piranamonte, “That I find really fascinating.”

– (Guardian service)