Cullalvera Cave is located in the municipality of Ramales de la Victoria, capital of the comarca of Valley of the Asón River. The entry for this cave near the village arises from a Cantabrian oak, and it is part of a karstic complex about 12 km (7.5 mi) in size, in which a multitude of geological forms shaped by water over the course of thousands of years can be found. These forms in conjunction with other prehistoric remains make the cave one of the most visited of the region. Remains of a small reservoir and rock art, both from the Paleolithic have been found here.