Ключевые слова: artificial tunnels, asia, building, caves, china, cliff, dangerous, digging, drive, effect, engineering, environment, extreme, features, geology, guoliang, henan, history, huixian, landscape, miracle, mountains, nature, outdoors, physiognomy, ravines, road, rocks, scenery, scenic spot, site, steep, structure, topography, traffic, transportation, travel, vision,