The Castles of the Assassin
Those who favor ambitious excursions and unusual historical episodes are recommended to hire a car and a guide to go near the source of the Alamut river on the southern foothills of the Alborz Mountains (requiring one full day for the return journey). There, fortified eagles' nests recall unbelievable but authentic adventures of the "Old Man of the Mountains" -Hassan Sabah, The Grand Master (1040-1124) -and of his sect of " Assassins" or "Hashashins"
The historic fortresses are known as the Castles of the Assassins, which were first introduced into European literature by the returning Crusaders, and madfamous this century in Dane Freya Stark's classical Valleys of the Assassins. These were the heavily fortified lairs of the adherents of a bizarre religious cult, based loosely on tprecepts of the Ismaili Sect. The cult was founded in the 11th century by Hassan Sabah. This heretical and widely feared sect sent out killers throughout the region to murder the leading political and religious figures. Its followers, the Hashishiyun, were so called because of their leader's alleged cunning ruse of taking them inbeautiful secret gardens (filled with equally enticing young maidens), getting them stoned on hashish and then sending them out on their homicidal assignments under the illusion that Hassan Sabah had the power to transport them to paradise.
The cult at its height extended from Syria to Khorassan. Until 1256, when the Mongols captured its castles, the Assassins spread tear throughout the region, although some scholars claim that their reputation was exaggerated.

As one might expect, the outlaw mountain hideaways were designed to be impregnable and inaccessible, and to this day it is still extremely difficult to visit them; a complete tour of the castles in this region would take about a week on horseback with a local guide. Many of them are only accessible to experienced and well-equipped mountaineers.
However, the castle of Alamut, one of the most famous of all, is nowadays more or less accessible by 4wD in dry weather, if one can find a guide or driver in Qazvin willing and able to take you there. It was originally built in 860, and captured in 1090 by the Assassins, who occupied it until 1256.
There are many buildings and places of interest in Qazvin, which you will encounter when strolling through the streets of the town. Be careful not to miss the Qazvin Museum. Qazvin is also noteworthy for its wooden houses with peristyles painted blue, pink or mauve; and so charming that they may seduce you to rise early in the morning and photograph them before having breakfast.