Introduction to Summer Spring: One of the natural caves formed by the stacking and overlapping of collapsed boulders. The cave is vertical, with a wide space inside the cave. The entrance is low and the exit is high, with a drop of about 15 meters. Due to the thermal insulation effect of the huge thick mixed rock mass, the temperature inside the cave remains at about minus 5 degrees Celsius all year round. In midsummer, the air is freezing and it feels like the depths of winter. A visit to the cave allows you to experience the changes in the four seasons of spring, summer, autumn and winter.