In the municipal area of Limone Piemonte it is still possible to recognize some stretches of the road that in Roman times connected the Vermenagna Valley to the Roya valley through the Colle di Tenda. These fragments of history are today enhanced by a hiking itinerary that links Limone Piemonte to Limonetto, starting from Piazza San Sebastiano and intersecting with the SS20 main road. The best-preserved section is the one that branches off to the right of the SS20 at the sixth hairpin bend to lead to the meadows of San Lorenzo where it is possible to observe Roman construction techniques of paving and masonry with the use of large reddish pebbles. There is no definite information on the use of this path, in any case outside the municipal territory the Roman mark also remains in the ancient name of Imperiale, a hamlet of Roccavione, located right on the route of the ancient road that passed on the right orographic side of Vermenagna, still largely viable today.
About two thirds of the way between Limonetto and the meadows of San Lorenzo is a milestone, a column placed by the Romans on the most important routes to indicate the distance in miles from Rome or from a city of the Empire, which marks the fifth milestone.