Firdous e Bareen (or فردوس برین in Persian and Urdu) was the name of the ancient Persian garden, supposedly located in the fortress of Alamut, in the Elburz mountains of Northern Iran, in which Hassan-i-Sabah and his band of Nizari Ismaili Shiite Hashshashin took refuge.
According to some accounts, this Paradise garden, imitating paradise or heaven, was furnished with all luxuries of life, even a rivulet of wine and was used to recruit Sabah's assassins. The recruit was drugged to simulate "dying," only to later awaken in a garden and be served a sumptuous feast by virgins. The supplicant was then convinced he was in Heaven and that Sabah was a minion of the divinity and that all of his orders should be followed, even to death.
The novel Firdous e Bareen, written by Indian Muslim novelist Abdul Halim Sharar, gives a biographical account of Hassan, a youth lured and captured by Sabah's men and then forced into his assassination machinery.
Firdous E Bareen is also a song on the album In the Absence of Truth by the Progressive Metal band Isis.