You can pass by here and think that you are simply in front of another area of limestone rock, so abundant in this area, but La Lastrera is much more than that, it is the abrasion ramp through which the glacier plunged into the Asón valley. . In this area during the Quaternary, the glaciers reached the lowest level in southern Europe, reaching 400 meters above sea level. Be very careful not to enter it on foggy days or, above all, with snow, you can rush into one of its large cracks.