Continuous erosion of the river Urtxuma created this cave some 14,000 years ago. A guided tour through its galleries will open up a hidden world of stalagmites and stalactites.
It is believed that a small congregation of Augustinian Canons established a pilgrims hospital here in the 11th century. In the 12th and 13th centuries the hospital was occupied by the Order of Canons Regular of Prémontré, also known as the Premonstratens
There is a hiking trail crossing the four villages of the area. The path, signed by small blue horses drawn on rocks, is named “pottokaren bidea” (the way of the horse), located between grassland and forests.