 The commune's highest point, Montoliu de Perellós (707 meters, a summit located next to the river Aude), stands as the northernmost point in Catalan-speaking countries.Opoul-Périllos spreads over a large area of 5,053 hectares (12,486 acres).In its present form it dates from January 1, 1972, when both villages where integrated into one single commune (Perellós, a tiny hamlet located some 10 km up into the mountain, had been virtually deserted since the end of World War II, the 1968 census returning just 4 inhabitants).