Located in the northwestern part of Shangri-La County, Napa Sea is a seasonal lake in the plateau. The four seasons of Napa Sea have their own characteristics. In the late summer and early autumn, it is the rainy season. At this time, the water is large, and the Napa Sea is a large lake. The summer water is full, the grass grows with small flowers, and the sheep, cattle, and horses graze in groups, blending with the grasslands. The autumn grasslands are golden and the snow peaks are reflected in the lake. In the dry season of winter and spring, the lake surface shrinks or even dried up, turning into a large swamp.