Introduction to Shenyan Cave: Shenyan Cave is the most mysterious and unpredictable, filled with smoke all year round. Smoke pours out of the cave entrance, or floats and rolls like huge waves; or slowly rises, forming colorful clouds and a myriad of phenomena. The cave is gloomy and cold, with stone pillars, stalagmites and stalactites scattered throughout the cave. The cave passage is tortuous and confusing, just like the "Eight Arrays".