A short train journey from Sousse took us to the small town of El Djem. The attraction here is the third-century Roman amphitheatre that you can pay to enter. Health and safety is not an issue in Tunisia like it is in Britain. A bit of tattered rope is the only thing stopping you from falling from the third floor onto hard stone, so if you're going to take children into the amphitheatre you'll have to keep a close eye on them.
The ancient amphitheatre is well worth visiting, though. You're able to clamber up its dusty steps and wander around its chambers, and it's possible to pay a little more to buy the right to take photographs inside the amphitheatre. The view from the highest level is pretty impressive, looking down along a road so straight that it must have been left by the Romans.
Apart from the amphitheatre, El Djem offers a museum of Roman mosaics which are surprisingly well preserved. The Restaurant Bonheure was a nice place to eat except for the children's table mats that were placed on every table. The wind around our outside table was so strong that one of these brightly-coloured mats was whipped off of our table and hit a local diner in the face. Luckily he was calm about it.