Introduction to the mountain gate: The mountain gate is a stone three-vote arch. The three door openings symbolize the "three realms". Stepping into the mountain gate means jumping out of the "three realms" and entering the fairy cave. The stone wall of the mountain gate is carved with patterns such as flowing clouds, cranes, and flowers. The sword technique is vigorous and the shape is exquisite. There is a palm-sized stone monkey hidden in the relief on the east side of the gate in the middle. There is a legend in old Beijing: "The gods have no trace." "Only the stone monkey is left in the temple." This stone monkey has become the incarnation of the immortal, and visitors to Baiyun Temple must touch it with their hands to seek good luck.