Karaj is a city in and the capital of Karaj County, Alborz Province, Iran. At the 2006 census, its population was 1,377,450, in 385,955 families, making it the fifth-largest city in Iran after Tehran, Mashhad, Isfahan and Tabriz.) It is situated 20 kilometres (12 mi) west of Tehran, at the foothills of the Alborz mountains. However, the city is increasingly becoming an extension of metropolitan Tehran.
Karaj is mostly famous because of its academic and educational complexes along with tourist attractions.
The history of Karaj dates back many centuries. The stone built Zoroastrian fire temple of Takht-e-Rostam from the Parthian era is a testament to this.
The Soleimanieh palace (currently housing a college of Agriculture), the mausoleum of Shahzadeh Soleiman, Imamzadeh Rahman and Zeid Palang Abad-e-Eshtehard are other historical relics of the Karaj area.