6 Best Sights in Fez and the Middle Atlas, Morocco

Volubilis's best set of mosaics, not to be missed, is in the House of Venus. Intact excavations portray a chariot race, a bathing Diana surprised by the hunter Actaeon, and the abduction of Hylas by nymphs—all still easily identifiable. The path back down to the entrance passes the site of the Temple of Saturn, across the riverbed on the left.

Rising out of fertile plains and olive groves, the impressive triumphal arch of Volubilis is the center point of the ancient Roman site. Decorated only on the east side, it is supported by marble columns, built by Marcus Aurelius Sebastenus to celebrate the power of Emperor Caracalla.

The house of Dionysus and the Four Seasons is about halfway down the Decumanus Maximus; its scene depicting Dionysus discovering Ariadne asleep is one of the site's most spectacular mosaics. Elsewhere along the Decumanus Maximus, the small spaces near the street's edge held shop stalls, while mansions—10 on the left and 8 on the right—lined either side. 

One of the most important houses in the Roman ruins is the House of Orpheus, the largest house in the residential quarter. Three remarkable mosaics depict Orpheus charming animals with his lyre, nine dolphins symbolizing good luck, and Amphitrite in her sea horse–drawn chariot. Head north from here to explore the public Baths of Gallienus and freestanding Corinthian pillars of the Capitol.

Named for its superb floor mosaics portraying a bevy of frolicking nymphs in a surprisingly contemporary, all but animated, artistic fashion, the House of the Bathing Nymphs is on the main street's right side. The penultimate house has a marble bas-relief medallion of Bacchus. As you move back south along the next street below and parallel to the Decumanus Maximus, a smaller, shorter row of six houses is worth exploring.

The ancient town's greatest mansions and mosaics, including the famous House of the Ephebus, line the Decumanus Maximus from the town brothel north to the Tangier Gate, which leads out of the enclosure on the uphill end. The house, just west of the Arch of Caracalla, is named for the nude, ivy-crowned bronze sculpture discovered here (now on display in Rabat). The cenacula, or banquet hall, has colorful mosaics with Bacchic themes. Opposite the House of the Ephebus is the House of the Dog, where a bronze canine statue was discovered in 1916 in one of the rooms off the triclinium, a large dining room.