Provincial nature reserve with 497.7 m above sea level and an area of 287 ha, lies in the Rongbian town of Gongjing district. The water area of Jianshan Lake is 38 ha, which is full of water all the year with the beautiful and changeable scenery. The cable bridge is high up over the lake, which is like a rainbow out of the water. If you walk in it, you can see the clear ripples and the water and sky blended in one color. This makes you feel the mountain and water are full of tenderness. The green pines, firs, camphor trees, heath, bamboo and so on are all over the mountains. If you stroll on the road in the shade of the trees, you will enjoy yourself.