Much of the system was the result of the Incas claiming exclusive right over numerous traditional routes, some of which had been constructed centuries earlier mostly by the Wari Empire. Many new sections were built or upgraded substantially: through Chile's Atacama desert, and along the western margin of Lake Titicaca, serve as two examples.[1]:242[7]:97 The Incas developed techniques to overcome the difficult territory of the Andes. On steep slopes they built stone steps resembling giant flights of stairs.