قلعة ألموت
A serious internal threat to the Seljuqs during their reign came from the Nizari Ismailis, a secret sect with headquarters at Alamut Castle between Rasht and Tehran. They controlled the immediate area for more than 150 years and sporadically sent out adherents to strengthen their rule by murdering important officials. Several of the various theories on the etymology of the word "assassin" derive from these killers.