Sa'd al-Saltaneh is Qazvin's strongest single sight: a large Qajar-era caravanserai joined to the bazaar by brick passageways, vaulted halls, and courtyards. It has been restored into a working mix of craft shops, cafes, galleries, and quiet corners where the scale of old overland trade still makes sense.
Come in the morning for cleaner light through the domes, or late afternoon when local shoppers give the complex more life. It is central enough to combine with the bazaar and the Jameh Mosque on the same walk.