This glen, which used to be called Ashdow, is a chasm up to 70 feet deep, and, in places, no more than 15 or 20 feet wide at any height. It was carved through the Old Red Sandstone by the Carnock Burn. The burn flows around a prominent stone called the Devil's Pulpit, whose name is now often applied to the glen as a whole. Near that stone, a steep stairway, built long ago in a crevice, descends into the gorge.