The pass is situated south east of Saint-Jean-Pied-de-Port. Starting from Auberge de Laugibar (north east), the Port de Larrau is long. Over this distance, the climb is (an average of 7.9%) with long sections at over 10% and the maximum gradient of 13% near the summit. Between the village of Larrau and the summit the climb passes over the Col d'Erroymendi at .