This medieval building, next to the Grand Mosque of Natanz, is located on a platform about 2.5 meters above ground.
Originally, it had four vaulted arches that reached above. Only the ruins of two isolated northern walls and their supporting arches from the south survive today. These four arches covered an area of around 122 square meters and were supported by two platforms.
Built of river stones and a gypsum and earth mortar, the walls had a thin layer of gypsum applied to them. The bases of the vaults were decorated with squinches, or decorative brackets, which added to the building's visual charm. Two squinches and one arch remain intact on the southernmost side of the structure, which is the best-preserved.
In 1311 (1932 CE), the Sassanian Fire Temple of Natanz was officially registered as one of Iran's national monuments under the registration number 187.