Tralcan (mapudungun for thunder) is a triangular shaped mount near Riñihue Lake, Chile. It is located south of the outflow dividing western Riñihue in two arms. Despite been sacred for the huilliches for centuries, the mount became famous when several landslides near Tralcan dammed the Riñihue Lake, after the Great Chilean Earthquake. The water levels in the lake rose more than 20 meters and became a threat to the existence of Valdivia city. These event come to be known as The Riñihuazo ("El Riñihuazo" in Spanish). There is evidence that a similar landslide occurred in 1575.