Pasabag Valley, also known as Monks Valley was once home to a hermitage of Christian monks who sought refuge in the valley's fairy chimneys during the early years of Christianity. They lived in the caves and chapels carved into the rocks, and some of these structures can still be seen today. The valley's fairy chimneys, which are tall, cone-shaped rocks formed of soft volcanic tuff, have been eroded by wind and water over thousands of years to create a variety of bizarre shapes and formations.They are formed from layers of volcanic ash and basalt, which were deposited during a series of violent eruptions millions of years ago. The ash and basalt were later covered by a layer of tuff, a soft and easily eroded rock, which formed the upper portion of the fairy chimneys.