Fyke Isle is a small island in Velen, located in Lake Wyndamer between Oreton and Frischlow. At one point a sorcerer named Alexander was using the tower on the island to continue his research on epidemiology and, in particular, the Catriona plague. Sometime later his patron, Vserad (the former Lord of Velen and previous owner of Crow's Perch) fled to the tower with his family after he got news of approaching Nilfgaardian armies.
Later on, some enraged peasants stormed the tower to kill the lord and his family. His daughter, Anabelle, survived the attack as she used a magic potion given to her by the mage that put her in a corpse-like state of paralysis. However, when she woke up she was unable to move and the rats ate her instead. Her ghost has wandered the tower since this incident.
In the western part of Fyke Isle is a circular area marked out with stones. Here, the Pellar and his community take part in Forefathers' Eve.