Acqualagna lies along the ancient Via Flaminia, south-west of the Furlo Gorge, inside which the Romans dug two tunnels in the rock at the point where transit was most problematic: the large tunnel, completed in 76 A.D. at the behest of the Emperor Vespasian, is still open to pedestrian and vehicular traffic. The area is part of the Furlo Gorge State Nature Reserve. Near what is now the village stood a Roman city, Pitinum Mergens, which was destroyed by Alaric: the inhabitants who survived the destruction founded the castle of Montefalcone from which, in the late Middle Ages, the village was formed. During the Middle Ages it was ruled by the Montefeltro family, lords of Urbino. The abbey of San Vincenzo al Furlo is definitely worth a visit. But Acqualagna is not only history and nature: at a national level it is defined as the "Truffle Capital", and events and shows are dedicated to this precious tuber. Not to be missed, however, is the National Truffle Fair, held every year between October and November.