Greater Tehran is the metropolitan urban area in Tehran Province that covers the contiguous cities of Tehran, Ray, Shemiranat, and other areas.
According to some estimates, Greater Tehran hosts a population of close to 15 million residents.
Tehran metropolis is situated mostly in Tehran County, but also continues over some areas in Shemiranat County, Rey County, and Eslamshahr County, Damavand County, Firuzkuh County, Karaj County, Nazarabad County, Pakdasht County, Robat-Karim County, Savojbolagh County, Varamin County and Shahriar County.