An
iwan (Persian:
eyvan,
Iwan, also spelled
ivan, Turkish: eyvan) 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. Since the definition allows for some interpretation, the overall forms and characteristics can vary greatly in terms of scale, material, or decoration. Iwans are most commonly associated with
Islamic architecture; however, the form was invented much earlier and fully developed in
Mesopotamia, around the third century CE during the
Parthian period.