It is estimated that this underground city which was discovered in 1972 in Ozkonak town at 14 km north of Avanos, is a four storey city. The size could not been determined exactly because of incomplete cleaning of the site. You can see several rooms, large saloons, slim and narrow ventilation chimneys, water well, a must house, and rounded key stones in the sections opened to visits. There are some holes opened at the roof of the corridor in front of key stones in order to use them in case of an attack. This kind of structure is unique that can not be found other underground cities in the region.