Bulla Regia is one of the most interesting Roman sites in the country, built above and (to keep cool) below the ground.
Visit the ruins of the Forum, the Memmian Baths, the Palace of Fishing (see the basement fountain) and the House of Amphitrite. Mosaics are often the highlights of these sites, but the buildings with mosaics are normally kept locked, so you may need to look around for a caretaker to open them.
80 mi/130 km west of Tunis.