Tus Citadel
The Citadel of Tus is a Sasanian era citadel, located in Tus, Razavi [Khorasan province], Iran.
It is made of brick and is rectangular in shape, having four circular towers at each corner, with two more circular towers in the inner structure. Not much remains of the structure; however, its size is comparable to other large citadels of the Sasanian era.