El Haouaria's dramatic, rocky coast was quarried by the Carthaginians and the Romans, who sought the highly prized, easily worked yellow sandstone for their massive construction projects, such as the Colosseum in Rome and the amphitheatre at El Jem. Because the quality of the stone was much better at the base of the rock face than at the surface, workers tunnelled into the cliffs, and the result after almost 1000 years of digging is a series of caves stretching along the coast.
Almost all of the caves are now fenced off and cannot be entered, but it's still a beautiful spot where you can wander through mini-ravines spotting ancient chisel indentations as crashing waves provide a peaceful soundtrack.