Lake Arreo-Caicedo is located in the southwestern quadrant of Álava, between the villages of Caicedo-Yuso and Arreo, in the municipality of Lantarón.
The Caicedo-Yuso or Arreo is the most important natural lake in the Basque Country. This area, at a height of 680 meters, is the only example of a permanent lake system in Euskadi. Its interior features a vast expanse of marsh mallow, algae grow in the deeper waters and a carnivorous plant called “utricularia”or bladderwort.
Located at the end of the diapir of Salinas de Añana, which feeds salt water to the Salt Valley of Añana, a visit to the lake makes it possible to enjoy varied vegetation, the holm oaks and gall oaks on the slopes surrounding the lake, and remarkable water related communities, with both freshwater and salt water species.
This wetland that accommodates an extraordinary biodiversity has a stable population of coot and other water birds, as well as being a staging area for migratory birds. It belongs to the Natura 2000 Network and holds the status of Wetland of International Importance.
In the immediate vicinity is the medieval necropolis of San Vicente and the medieval chapel of the Virgin of the Lake, destination point of a pilgrimage that is held on the Eve of Corpus Christi. Similarly, nearby is the Monastery of San Juan de Acre, the Palaces of the Ozpinas and Herran families and the Church of Sta. Mª de Villacones.
In the municipality of Lantarón. Cuadrilla de Añana / Añanako Eskualdea.
Located on the Sierra de Turiso, on the southern edge of the diapir of Salinas de Añana, it can be accessed by following the A-2622, that goes from Pobes to Salinas de Añana. Before reaching Salinas de Añana take the A-4318, which leads to Viloria, and from here continue to the village of Arreo. It is advisable to continue along the road for a kilometre or so, until reaching the hermitage of Nuestra Señora del Lago, located about 100 meters to the left of the road.
It is accessible by car, bicycle or on foot, however, it is advisable to access it from the village of Salinas de Añana, by following the Arreo or Viloria footpath.
It is not easy to find, as its location is not clearly signposted. It is advisable to leave the car before arriving at the lake, as there are no parking facilities.