The pass (altitude 1 915m) is where the waters of the Ariège, a tributary of the Garonne, flow towards the Atlantic; the Sègre, a tributary of the Ebro, runs towards Spain and the Mediterranean. Since the Puymorens Tunnel was opened in 1994, it has been possible to avoid the pass. Une Cascade de Lumière, the 16m-high polychrome glass sculpture above the tunnel entrance, on the Pyrénées-Orientales side, is a stunning work by Josette Rispal.