With an average width of six to eight metres, it is the tributary of the Nive from Baigorri which is the most important, contributing to the main river.

With the other source above the village of Esterençuby the clear waters flow down for 15 kilometres (9,4 miles), through the lower part of the town of Saint-Jean-Pied-de-Port, before joining the Laurhibar tributary and the Arneguy Nive at the spot know as “the three waters” at Uhart-Cize to form the main river.

This semi-chalk water stretch of river is productive and contains a good stock of brown trout with an average size of 25 cm (10 inches). Its features allow for either live bait fishing, fly or with lures.