Iwan

An iwan (Persian: ایوان‎‎ eyvān, Arabic: إيوان‎‎ 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.

The root for this term is Old Persian 'apadana' (see Apadana palace at Persepolis) where king Darius I declares in an inscription, "I Darius,........ had this 'apadana' constructed.." This is a name given to this particular palace in modern literature, although the name simply implies a type of structure—the iwan, not a particular palace. The term in Old Persian stand for "unprotected" (a-pâd-ana), since the design allows for the structure to be open to the elements on one side, whence the term. At Persepolis, however, the 'apadana' takes the form of a veranda, where instead of a vaulted hall, there is a flat roof held up by columns—but still, open to the elements on only one side. A comparable structure would be found 2000 years later in Isfahan at the Palace of Chehel Sotoun. By the time of the Parthian and the Sasanian dynasties, iwan had emerged as two types of structure: the old columned one, and a newer vaulted structure—both, however, carrying the same native name of apadana/iwan, because both types are "unprotected" (open on one side to the elements).

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