El Jem or Dougga: which Roman site fits one day?

Deciding between El Jem or Dougga is genuinely hard, because both are World Heritage sites and yet they give you completely different things. One grabs you in the first second; the other has to be earned and rewards patience.

A nearly intact Roman amphitheatre built for around 35,000 spectators, planted in the middle of a small town in central Tunisia. That incongruity is what strikes you: you drive along ordinary streets, turn at a junction, and a three-tier arcaded facade blocks the horizon.

• The tiers, which you climb to the top. The view over the arena and the town's white roofs is the shot everyone brings home.

• The undergrounds, where beasts and gladiators waited before being hoisted into the arena. Far more accessible than those at the Colosseum.

• The archaeological museum, minutes away, often skipped and yet remarkable for its Roman mosaics.

Allow 1 h 30 to 2 h for the whole thing. If you have to sacrifice something for lack of time, sacrifice the museum, not the undergrounds.

Not a monument but a town. Dougga spreads over about sixty hectares on a hillside, and its urban fabric is still legible: you follow streets, walk into houses, pass in front of shops.

• The capitol, whose facade and six columns still stand at full height. It is the site's postcard image.

• The theatre, built into the slope with a view over the plain. You sit in the tiers and the acoustics still work.

• The public latrines at the baths, horseshoe-shaped, telling you more about Roman daily life than ten information panels.

• The Libyco-Punic mausoleum, older than the Romans, a reminder that the site was Numidian before it was Roman.

Allow 2 to 2 h 30 to go round without rushing. The ground is uneven, sloping, with loose stones in places. Closed shoes are essential and flip-flops are out.

It is the second site of the Dougga day, and often the one visitors talk about most afterwards. Facing scorching summers, the Roman inhabitants of Bulla Regia built part of their villas below ground level.

You go down a few steps and find yourself in a third-century living room, columns in place and the mosaic still exactly where the craftsman laid it. The temperature drops several degrees, which was precisely the point. Few Roman sites let you experience the inside of a house this way.

If you are still torn, that detail is what should tip the balance towards Dougga for anyone curious about architecture.

The El Jem day does not stop at the amphitheatre. The afternoon is spent in Kairouan, regarded as the fourth holy city of Islam. The contrast is what makes the day valuable: Rome in the morning, the beginnings of Islam in the Maghreb in the afternoon.

• The Great Mosque, with its vast courtyard and square minaret, one of the oldest in the Muslim world.

• The Aghlabid basins, circular reservoirs of remarkable hydraulic engineering.

• The medina, its carpets, its date makrouds and a souk far less touristy than the one in Tunis.

Watch out for Friday: access for non-Muslim visitors to the Great Mosque is restricted that day, and opening hours vary by season.

And if you have two days, do both with a rest day in between. It is the best way to grasp Tunisia's Roman layer, one of the densest around the Mediterranean. Both days are among our seven private excursions.

Whether you pick El Jem or Dougga, the logistics barely change: leave around 7.30 am, come back late afternoon, and follow the same decisive habit of arriving before the coaches. It is the practical details that separate a good day from a poor one.

• Hours: sites open around 8 am and close between 5 pm in winter and 7 pm in summer, with seasonal variation.

• Tickets: paid on site, in dinars. Card payment is not guaranteed at isolated sites.

• A guide on site: at Dougga the €20 to €30 is genuinely worth it, since the site is large and poorly signposted. At El Jem the amphitheatre speaks for itself.

• Accessibility: Dougga is hard going in a wheelchair. El Jem is accessible at arena level, but not the upper tiers.

• Water: plan 1.5 litres per person in summer. There is sometimes a single vendor at the Dougga entrance.

One last thing not to attempt: doing both sites the same day. They are more than three hours of driving apart, and any offer combining them sells you transport rather than sightseeing.