Very close to the densely populated, industrial plain of Oria, a clean water tributary with abundant meanders passes through a solitary valley, which acts as a green lung. This is the winding Leitzaran river, which extends from Leitza (Navarre) to Andoain, and which was declared a 'protected biotype' in 1995.
This meandering river allowed for the establishment of 18 riverside hydraulic ironworks, the remains of which can still be found today. We can also find the succession of tunnels excavated for the former Plazaola railway, which connected Gipuzkoa to Navarre from 1914 to 1953. Its tunnels and bridges are now a quiet Green Route which is much appreciated by cyclists and trekkers.
Flora and fauna
The Leitzaran is, above all, a trout river, although it is also a habitat for many other animal species: Pyrenean newts, Iberian desmans, eels, minnows, kingfishers, dippers... These animals live amongst alders, pines, larches, oaks and some unusual plants such as the 'soldanella villosa'.
From the centre of the town of Andoain we have two options: 1. Take the GI-3091 road and, after 2 km, you will reach the entrance to Leitzaran valley, which is duly signposted. 2. Take the Trentxiki Green Route in Plazaola, which is next to Andoain tourist information point (Urigain building), just a few metres from Andoain Town Hall. In this case access is limited to pedestrians and cyclists, a distance of 2 km. It is duly signposted. - From Andoain, take the A-15 (motorway to Navarre), and leave at Elduain and Berastegi exit junctions.