Only then can birds cross the sky, and clouds soar to the heavens. A seven-story wooden building suspended thousands of feet high, a mysterious history sealed away, and a perplexing enigma that leaves people puzzled. The Wudang Mountain, stretching for eight hundred li, is characterized by continuous peaks, crisscrossing gullies and thousands of cliffs emerging one after another. In ancient times, many reclusive practitioners chose to settle here, and Tianxian Rock was one of them. This place is rarely visited by people. The mountain paths are so narrow that one can hardly take a step. Although one can enjoy the view from afar, one cannot appreciate it up close. The wooden tower built along the rock hangs above the thousand-meter peak, becoming a castle in the air, towering and lofty, intimidating yet yearning to be seen. Who built such tall buildings here? What wisdom lies deep within the perilous wooden building? Not long ago, the natural landscape investigation team of Wudang Mountain climbed over mountains and crossed valleys to reach Tianxian Rock, uncovering this long-buried secret.