The Circle of Light was an important feature of Yew in the time of Ultima III. A sacred site of the city's druids, the Circle of Light is a unique structure made of rings of flame and water, with four clerics forever watching over it. It was rumored to be a place where the pious would have wisdom imparted to them. When the company of the Stranger came upon it, an earnest prayer revealed to them the word evocare, the exhortation needed to pass the Great Earth Serpent, which then guarded the Isle of Fire.