Garmsar city is the westernmost city of the province; It is limited to Firouzkoh and Damavand from the north, Aradan city from the east, Kavir Namak and Qom from the south, and Varamin from the west. The distance from this city to the center of the province is 119 km and to Tehran is 100 km.
The name of Garmsar was Khoran during the Parthian period, due to the fact that Garmsar is located next to the desert and is lower than its neighboring places, on this occasion the name "Khoran" put it The meaning of this name is given in the Avesta book Sun and Moon.
The Habla River, which originates from the central Alborz mountain range, irrigates the surrounding areas of Garmsar. Among the main agricultural products of this region,  wheat, cotton,  melon,  Pomegranates and figs can be mentioned. And the most important field of handicrafts in this city is all kinds of rugs with local motifs and designs.
Among the attractions of Garmsar, we can refer to the Siahkoh historical complex located in the desert national park, stone pavement road, Stonevand historical fort, Bagheri historical house, cotton factory and warehouse complex, Shah Abbasi Ivan Kay Caravanserai, Ben Koh tourist sample area and salt caves. made.
The city of Garmsar was called Qashlaq until recently, and still old people pronounce it Qashlaq. In the past, Khawar included 4 blocks, which are:
                                                                           
1- Qashlaq Block     2- Rikan block      3- Yatri Block    4- Block Arada