An iwan (Persian: ایوان‎ eyvān, Arabic: إيوان‎ Iwan) is a rectangular hall or space, usually vaulted, walled on three sides, with one end entirely open. The formal gateway to the iwan is called pishtaq, a Persian term for a portal projecting from the facade of a building, usually decorated with calligraphy bands, glazed tilework, and geometric designs.