The castle is square and it was built in dimensions of 70m by bricks 30cm. it is two-storey, upper storey has a cross hall and some rooms surround it and lower storey has some connenctive way. Some people believe the castle is a remnant of Madine musa which is made by the order of Musa Al-Hadi, abbasi ruler, in 168Hq. others have been attributed it to Meimun Ibn 'Un Kateb. Earned earthenwares pull back the oldness of it to Ale buye era.
The castle is placed on the end of Salamgah St. and in front of the eastern entrance of Imamzade Hossein.