Friday Mosque of Varamin, Varamin, Iran

Located forty-two kilometers south of Tehran, the Friday mosque of Varamin was built in 1322 on the orders of Abu Sa'id, the son and successor of Oljeitu (also known as Muhammad Khodabandeh, the eighth Ilkhanid ruler in Iran).

The mosque is best known for being the earliest surviving example from the Mongol period, and intended to embrace the ideal four-iwan plan in one construction. This ideal plan originated in the Masjid-i Jami' at Zavareh, considered the prototype for this kind of mosque that developed during the Seljuk period. 

The decorative treatment of the building's surfaces is rich: the materials employed include plaster, glazed and unglazed terracotta, and glazed tile-mosaic work. These materials clad the building's brick structure. The portal iwan is decorated with glazed terracotta in dark and light blue forming a geometric arabesque on a background of unglazed terracotta. Its vault is constructed in such a way that tiers of bricks laid horizontally jut out to different degrees at different levels to form a semi-dome. 

The mosque's western part has almost entirely disappeared over the years, but the rest of the structure (almost half of the original along the north-south axis) was recently restored. It includes, to the south, the sanctuary (comprised of a domed chamber, ten meters per side) with its iwan overlooking the court; the main portal iwan is found opposite it, on the north side of the court. In addition to the main portal, two lateral entrances were formerly located on the east and west. Of the two, only the eastern portal exists today. The design accentuates the space of the domed chamber by raising its dome higher than the level of the other two iwans on the site. This impression of size is most prominent when one passes from the low vault of the iwan to the lofty space of the domed chamber, where the mihrab is situated on the south qibla wall. 

The iwan of the domed chamber is decorated with richly ornamented geometric patterns in terracotta, above which an inscription band runs horizontally and marks the beginning of the iwan's vault, which comprises a cluster of muqarnas units. These units are in turn constructed out of smaller bricks. 

Intricate plaster floral and vegetal motifs decorate the mihrab's niche as well as the wall surrounding its pointed arch. An inscription band frames the mihrab's portal, beyond which plaster spreads like a three-dimensional tapestry to cover the whole wall. The other three walls display geometric patterns in terracotta. In many areas, bricks are displayed so that they extend from the wall to highlight its sculptural qualities. 

The dome of the square sanctuary chamber was recently renovated and rises on top of a sixteen-sided drum with alternating windows, resting on an octagonal transitional area formed by four squinches. It is decorated with a sunburst medallion at its center from which descends an arabesque of a diamond geometric motif that expands with the curve of the dome. The spandrels of the arches of the four squinches are ornamented with glazed terracotta and incorporate in their vaults three tiers of muqarnases. Four windows are situated on the walls of the chambers, each between two squinches. 

For most contemporary architectural historians, the Friday mosque of Varamin continues to epitomize the first crystallization of a four-iwan mosque by the Il Khanids, but also a monumentality achieved by the delicacy of ornament, the display of rich materials, and the play of light and shadow of the sculptural architectural elements. (Source: Islamic Architecture Community)