The complex consists of a

mosque A mosque (; from ar, مَسْجِد, masjid, ; literally "place of ritual prostration"), also called masjid, is a place of prayer for Muslims. Mosques are usually covered buildings, but can be any place where prayers ( sujud) are performed, ...

, a

Bathroom A bathroom or washroom is a room, typically in a home or other residential building, that contains either a bathtub or a shower (or both). The inclusion of a wash basin is common. In some parts of the world e.g. India, a toilet is typically i ...

and an

Ab anbar An ''ab anbar'' ( fa, آب‌انبار, literally " Cistern") is a traditional reservoir or cistern of drinking water in Greater Iran in antiquity. Structure To withstand the pressure the water exerts on the containers of the storage tan ...

. Kushk Mosque is the oldest mosque in

South Khorasan Province South Khorasan Province ( fa, استان خراسان جنوبی ''Ostān-e Khorāsān-e Jonūbī'') is a province located in eastern Iran. Birjand is the centre of the province. The other major cities are Ferdows, Tabas and Qaen. In 2014, it wa ...

, and based on the evidence of its existing architecture, its original structure dates back to the early centuries of Islam.

Sources

Mosques in Iran Mosque buildings with domes National works of Iran Buildings and structures in South Khorasan Province South Khorasan Province articles missing geocoordinate data {{Iran-mosque-stub