In the Taoist architecture of Wudang, the mountain gate of the temple is of great significance. Entering the mountain gate means stepping into the divine realm. The main gate of Nan Yan Palace is ingeniously laid out by taking advantage of the terrain. Although it is small and unique, it fully embodies the standards of imperial architecture. Right next to the mountain gate is the huge Imperial Stele Pavilion. The Imperial Stele Pavilion is a unique architectural feature of the Ming Dynasty on Wudang Mountain, symbolizing the rank of palaces. In the pavilion, a huge turtle is carrying the imperial stele on its back. This not only symbolizes its long-term preservation but also demonstrates the practice of the "turtle" in traditional Chinese culture, where only the giant turtle is qualified to convey important orders to the world. The imperial stele pavilions of other temples on Wudang Mountain are usually built symmetrically on both sides of the central axis. However, perhaps due to the terrain restrictions, another imperial stele pavilion of Nan Yan Palace is built on the other side of a cliff far away. This gave rise to a riddle with Wudang characteristics: "The stele pavilion on the South Rock - Two never meet."