Shangri-La City, formerly known as Zhongdian, was renamed after the fictional paradise of James Hilton's "Lost Horizon" in an effort to promote tourism in 2001. Located in northwestern Yunnan province, Shangri-La is commonly used as a gateway into Tibet, but tourists also visit the city en route to the Ganden Sumtsenling Monastery, the largest in Yunnan province; Pudacuo National Park, home to almost 100 endangered species; and Tiger Leaping Gorge, one of the deepest river canyons in the world and part of a UNESCO World Heritage Site.