AKA the "Wasteland"
Vast desert in the Southlands, separating the two remaining cities of the Bakshevan Empire: Monterba and Altaban. It is dotted by terukh (oases), diminishing in number in the south. It was probably formed when the Bakshevan Empire was afflicted by the Drought which lead to its downfall, that was caused by the cursed blood of the White Kin as related in The Silver Spear of Gorimon.
The ruins of the lost city of Gorimon are rumoured to be there, and there may be some truth to this. The Cups Handler claims to have sourced many magical artifacts from there including the one he uses to detect magic, as Karek informs April.
According to Umber Ianos, 50 years ago he was chased into Ch'angagriel by the Mahk of Monterba's soldiers for seducing the Mahk's daughter. He claims to be the first person to cross the desert on foot, presumably to sail north from Altaban.
It is also home to the Giant Elgwan.
April has trouble reading the name Ch'angagriel when reading the delivery list of maps she has to deliver on behalf of Karek. Ironically, Sarah Hamilton also found it difficult, and her out-takes can be heard in the Book of Secrets.