This is one of Leptis' most significant monuments and the grandest likely introduction to the architectural excesses of the town. It was constructed in AD 203 to honor the monarch and his family, and to mark his visit to his native town.

The heart of the structure was built of limestone, bizarre for the time, and enclosed with a marble exterior. What you see today has been devotedly reconstructed by archaeologists to striking effect. It remains a work in progress.

The friezes attached to the arch are, in fact, imitations with the originals residing in Gallery eleven of the Jamahiriya Museum in Tripoli. Other unique elements of the arch are to be found in Room four of the Leptis Museum.