Chehel Dokhtaran Vault is located at the center of Damghan and behind Imamzade Jafar, both of which belong to Seljuk period. A Kufi inscription in the edifice says the vault was built in 466 A.H. (1087 A.D.) and has survived without cracks although the city is lying on the earthquake belt.
 

What is more interesting in the vault is its onion-like dome which is adorned by bricks with artistic images and an inscription. The building which used to be a family vault is 14.8 m high and in its famous inscription the deceased have sought divine mercy in their lasting residence.