What it is
A three-tier amphitheatre built in the 3rd century, among the largest in the Roman world and one of the best preserved. You can walk the upper tiers and go down into the underground passages where animals and fighters were held. A separate museum in the town holds mosaics from the surrounding villas.
Why go
It is the one site in Tunisia that needs no explanation or imagination. It is on the main road and rail line between Tunis and Sfax, which makes it an easy stop when moving south.
When to go
Any month; early morning or late afternoon in summer, because the stone holds heat and the arena floor becomes an oven. A classical music festival is held in the amphitheatre in July, which is the one good reason to be there in high summer. Allow two hours.
Most people stay Day trip.