Haftad-o Do Tan Mosque belongs to ninth century A.H. and it is located in Khosravi Street, at the beginning of the Grand Bazaar, Mashhad. This building has a chartaqi space (four arches space), cavity dome, two minarets and a porch. Haftad-o Do Tan Mosque has first been a tomb constructed by Amir Ghiyasuddin for himself and in later eras, it was converted into a mosque. Haftad-o Do Tan Mosque has been registered as a national monument of Iran.