Buchan caves were created almost 400 million years ago by underground rivers cutting through limestone rock. The formations are created by rain water seeping through cracks and dissolving some of the limestone. As each droplet comes through the roof it deposits calcite which crystallises in a small ring. In time, stalactites are formed on the roof of the cave, and stalagmites build up from droplets which fall to the floor. This cave known as Fairy Cave is so called as the white stalactites on the roof have a glowing crystal like appearance.