It is located between the towns of Llarduia and Eguino, in the provincial park of the same name.  

La Leze is a ravine-cave that crosses from north to south, a whole limestone massif located in the Sierra de Altzania, dividing between Gipuzkoa and Álava.  

All this area is ideal for climbing lovers, in addition there is also the climbing school of Llarduia and Eguino. The difference in levels between its northern and southern inlets causes the river to descend at impressive waterfalls.  

Its height reaches 70 meters in the highest areas and 20 in its widest sections. The galleries go over half a kilometre.