Also known as: Varamin Jame Mosque, Masjed-e Jaame-e Varamin, Congregation mosque of Varamin, Friday mosque of Varamin, Grand mosque of Varamin

Also known as : Jāmeh Mosque of Varāmīn (Persian: مسجد جامع ورامین‎‎ – Masjed-e-Jāme-e Varāmīn)
This mosque is one of the oldest buildings of Varamin city. Its construction began during the reign of Sultan Mohammad Khodabaneh and was completed during his son's rule Sultan Abu Sa'eed. This building consists of a Shabestan, portico, large brick dome, the structure beside shabestan and ten small arches along with one large arch in the middle.

This mosque 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. 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 Saljuq period. However, the Friday mosque of Varamin, especially its typically Mongol, nearly-square, small (25 by 25 meters) court, displays different proportions relative to the scale of the whole structure (66 by 43 meters) than those found in the ideal. The court was originally surrounded on its four sides by a one-story arcade covered with pointed barrel vaults.

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 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 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.

The Congregational Mosque of Varamin, is one of the most popular samples of Four hall mosques of Iran. The establishment of this mosque, has been by the Soltan Mohammad Oljayto (Khodabandeh),it had begun ,and it had been finished by his son Abu Saeed Bahador Khan, and was completed .and the dates from 722 to 726 Hejri Ghamari it is shown in the Basement and also near the main tower ,it is shown. This building in 1815 (h. g.), at the time of Shahrokh Teimuri has been remodeled.

In the beginning of northern straight of the building, and also at the southern end of entrance, the sight of Bazar (or the shopping area) is visible. The temple of surrounded sailings is ending to four different balconys, and there are two halls in the northern straight and two halls in the southern part as well. In the back of main Balcony the Gonbad or the Temple room is located. Other ceilings and also is twice as the size of main entrance hall. On the other hand the width and the tallness of it are 2/3rd of the length of the main hall. Therefore the main balcony is a little sized Balcony (the entrance with cover on the top, and it has specialized for the stand or sit of the Imam, or Khalife in the mosque), which is designed very simple and also glorious leading the whole scene. The supremacy combined with the glory and artful architectural match, are also covering the whole building especially the front balcony which is very special in this Mosque.
The top Main Entrance door of this Mosque is very interesting, and also it is painted on the side walls of the entrance with nice light blue it is covered by Ceramics and it is made very professional as well. This Entrance door, regarding the design and the perpetration, is like the Natanz and the Mosque congregational temple of Mozafari in Kerman. This mosque has two towers which are standing on two side by side bases.