Wikipedia
Kilan (, or more properly, Kailan, also Romanized as Kīlān; also known as Kilun) is a city in the Central District of Damavand County, Tehran Province, Iran. At the 2006 census, its population was 3,038, in 913 families.
The name is derived from the Kurdish tribe of Kailan/Khailan/Gailan who were settled in this region in the Safavid period. Only a few still speak Kurdish and mostly further up north toward Kelardasht. The local folklore, however, produces a folk etymology for the now mysterious name as "meaning ' Kingsplace.
In the mountain area of Kilan, leftovers were found from people living there about eighteen thousand years ago. The mountains around the town, like Dar Ali, are scattered with remainders from the Cenozoic.
As of 2006, there are around 3,000 inhabitants, with a remarkably high (75%) of the inhabitants of the town having academic degrees.
The name is a popular last name across the Islamic World. This is largely due to the impact of the famous medieval mystic, Abdul-Qadir Gilani, the Sufi master of the Qadiriyya Sufi order. The Prime Minister of Pakistan Yousaf Raza Gillani, for example, carries this as his last name. But this is because of their adherence to the Qadiriyya Sufims than belonging to the tribe or family by that last name.