Carcassonne is at about 90 km (56 mi) southeast of Toulouse in the space between the Pyrenees and the Massif Central of France.
It is at the crossing of two major traffic routes: the route leading from the Atlantic to the Mediterranean and that from the Massif Central to Spain, skirting the Pyrenees.
Both routes exist since ancient history.

The commune is in the valley of the Aude river.
Another river that flows through the city is the Fresquel river.
The Canal du Midi also flows through the commune.

The commune of Carcassonne has an area of 65.1 km² (25.1 sq mi), and its average altitude is 111 m (364 ft); at the city hall, the altitude is 110 m (360 ft).

The commune of Carcassonne is surrounded by the communes:
Carcassonne is at about 90 km (56 mi) southeast of Toulouse in the space between the Pyrenees and the Massif Central of France. It is at the crossing of two major traffic routes: the route leading from the Atlantic to the Mediterranean and that from the Massif Central to Spain, skirting the Pyrenees. Both routes exist since ancient history.
The commune is in the valley of the Aude river. Another river that flows through the city is the Fresquel river. The Canal du Midi also flows through the commune.
The commune of Carcassonne has an area of 65.1 km² (25.1 sq mi), and its average altitude is 111 m (364 ft); at the city hall, the altitude is 110 m (360 ft).
The commune of Carcassonne is surrounded by the communes:
Carcassonne