For an unbelievably relaxing hot-water soak, descend a windy, gorgeous mountain road to the isolated bathhouse of Hammam Mellegue, where you can bathe in an authentic 2nd-century spa fed by a natural spring. Overlooking the broad, sandy sweep of the murky green Oued (River) Mellegue, it's hidden away at the base of a dramatic escarpment surrounded by reddish bluffs dotted with pine trees.

Although much of the bath complex is little more than a roofless jumble of walls and arches, the caldarium (hot room) is an extraordinary place that remains virtually unchanged more than 1800 years after it was built. The only electricity comes from photovoltaic cells.

A large wooden door opens onto a steam-filled chamber, with a skylight set into the barrel-vaulted ceiling. Ancient stone steps lead down the pool, worn smooth by the feet of 40 generations and turned dark red by iron elements in the water. The pool is fed by hot springs whose waters emerge from the ground at 35°C. It is emptied by removing wet rags from the ancient drain pipes, connected by gravity with Oued Mellegue, and refilled from pipes connected to the spring. There are two chambers that separate the genders.

The water is slightly saline (you can drink it direct from the inflow pipe) and is said by locals to be good for rheumatism and problems of the digestive tract.

Bring a bathing suit, towel, flip-flops and plenty of drinking water. The hammam's caretakers offer massages, shampoo and soap for a fee.

A cafe and a few log cabins were under construction at the time of research, awaiting additional funding before they are completed.

Beloved by locals from Le Kef and Algerians from just over the border, Hammam Mellegue is an intimately local experience that doesn't attract many foreigners (mostly because its proximity to the border with Algeria means that the UK's Foreign and Commonwealth Office advises against all but essential travel).

There's a new road to the site, so online maps won't lead you in the right direction. It's a quick half-day trip from Le Kef, so ask locals for directions before setting off. You'll find the journey easiest with your own wheels, but you could hire a louage (shared taxi) for about 20DT one way with a set pick-up time.