Russian SU-27 fighter jets rehearse for an aerobatics show at Zhangjiajie National Forest Park. Tianmen Mountain is regarded as the symbol and soul of Zhangjiajie. Tianmen Mountain is the first recorded mountain in the history of Zhangjiajie. The highest peak is around 1518.6 meters above sea level. The mountain is named after the natural huge cave half way up the mountain just like a gate to the heaven, hence, the name Heavenly Gate Mountain.