A must see in Zhangjiajie. Please note that the National Park, Tianmen Mountain and Grand Canyon are 3 seperate areas and this in itself would be a half day/full day trip. The mountain itself is breathtaking, and although the 999 stairs are quite the challenge, it is very worth it! Please take time to explore the top area, it has a lot more views to offer. The weather is tempermental, we managed to get there when it was clear- it can get foggy quick though! We took Line A and would recommend this one to see both cable cars and areas.