A shabestan or shabistan (Persian: شبستان; Old Persian: 𐎧𐏁𐎱𐎿𐎫𐎠𐎴, romanized: xšapā.stāna, lit. 'night room' is an underground space that can be usually found in traditional architecture of mosques, houses, and schools in ancient Iran.
These spaces were usually used during summers and could be ventilated by windcatchers and qanats.
During the Sasanian Empire and the subsequent Islamic periods, shabestan also referred to inner sanctums of the shahs where their concubines resided. Later these structures came to be called زنانه zanāneh "women's residence" and اندرونی andaruni "inner private zone".[1]