Zhangjiajie is a city in northwest Hunan with a scenery problem: the best of it isn't in the city. The Wulingyuan scenic area, a UNESCO World Heritage Site since 1992, holds more than 3,000 sandstone pillars, many over 200 meters tall, wrapped in subtropical forest and fog. They look like karst, but they aren't: water and ice cut them out of quartz sandstone. In January 2010 the park renamed one of them Avatar Hallelujah Mountain.
It is crowded, steep, foggy half the year and priced like a theme park, and still worth the journey. Three days is the practical minimum: the park fills two, and Tianmen Mountain needs its own day. The Grand Canyon glass bridge doesn't fit. With a fourth day, add it.
Day one is Huangshizhai, the stream and the Bailong Elevator. Day two is Yuanjiajie and Tianzi Mountain, then the city. Day three is Tianmen Mountain, where only the short cave line runs for now. Start on a Tuesday if you can, since weekends and holidays turn the park into a queue. More on the country: China, or pair this with Guilin and Chengdu.