The first chamber after the initial nave, this room contains the casket of Sheikh Hassan. Born 1195 CE, said to have been a nephew of Sheikh Adi and the author of their religious text, the Black Book. (Thus making it the oldest surviving Kurmanji text. The room also has a stairway leading down to Zimzim spring, which is forbidden to non-Ezidis, and a doorway leading to the shrine of Sheikh Adi himself.
One of the tombs in the temple of Sheikh Adi is ascribed to Hasan-ool-Basri, whereas I have been assured that the Sheikh who is said to be buried there was a different individual, and one of their own sect whose descendants are still living at Ba-Sheaka. Badger 1852, p 112
Badger, George Percy. 1852. The Nestorians and their Rituals.