The principle story of the Garden of Alamût is taken from Marco Polo. An initiate who is selected for an assassination is drugged and taken to a garden or valley close to Alamût where he spends a night thinking he is being given a taste of paradise. Here he is given a taste of sensuous delights such as fountains flowing with milk, honey, wine and a full assortment of houris, virgins promised in the Koranic Paradise. After a night in this paradise, the Assassin was again drugged an told that he would spend an eternity in this paradise once he completed his mission.
A close inspection of the area surrounding will quicky show that this it is highly unlikely that the Garden was a physical garden of this world. The terrain in this area is arid, rocky and at an altitude that would not support the vegetation that was described in the chronicles of Marco Polo. The Garden if it did exist was either an allegory for some sort of initiation ceremony or the garden was part of a spiritual vision to which the candidate was given access to.