The southern highlands between the Aktarvkus and Mythlias, where the mountains break down into a chaotic landscape of steep ridges and narrow valleys. The name is earned: these hills have killed more travelers, soldiers, and would-be settlers than any other region of Kyagos.
The Kuru beast-warriors treat the Killing Hills as sacred ground. Their warriors come here to prove themselves, hunting each other and anything else that enters. Surviving a solo journey through the Killing Hills marks a Kuru as an adult; dying there is considered an honorable fate.
For everyone else, the Killing Hills are simply an obstacle—one of several reasons why overland travel between Tekos and the western city-states rarely happens. Better to take a ship around the coast, despite the dangers, than to cross terrain where everything is trying to kill you.