Volubilis is definitely an ancient Roman city where you should be careful about keeping a good eye with the ground. There are many mosaics here and an impressive quantity of them are in excellent conditions. Practically all that are of much value are fenced in, but not more than what allows them to be easily looked at.
Ironically all are fenced in in order to save them from the wear and tear of visitors' feet and shoes. Yet, the mosaics are really nothing more than decorated floors.
There are mainly three houses that you should stop by: House of the Euphebus right next to the triumphal arch; the House of Orpheus to the south near the olive oil presses; and the house of Dionysus near the Decumanus Maximus.