Located between the Vaux Mountain the north and the Eygues banks to the south, contiguous to the clue (rocky around a watercourse), the town of Nyons is the gateway to the Baronnies Provencal massif by the Eygues valley. From the fourteenth to the nineteenth century, its bridge was the only structure, upstream of Orange, to allow the crossing of the river in any season. The city becomes the point of passage for the commercial and military routes.