Caravanserai of Sa'd al-Saltaneh was built at the instigation of Sa'd al-Saltaneh (died in 1907 AD), the then Qajar governor of Qazvin. This caravanserai has a very beautiful historical area which is currently the biggest urban caravanserai complex in Qazvin. It was built by Sa'd al-Saltaneh, the then Qazvin governor, during the reign of Naser al-Din Shah. Caravanserai of Sa'd al-Saltaneh is the biggest urban caravanserai is Iran and one of the few Iranian caravanserais that contains several bathrooms, saray, arcade, shotor khan, chahar souq, Rasteh, mosque, tea house and so on. This caravanserai functioned as a trade house.
This historical monument was initially registered in the subset of Qazvin bazaar on December 8, 1937. Then it was separately registered under the name the Caravanserai of Sa'd al-Saltaneh and later on August 2, 2005, Sa'dieh Bathroom was separated from the caravanserai under the registration number of 12598.