Pudacuo is a national park covering Bita Lake (Bitahai) and Shudu Lake, about thirty kilometres east of Shangri-La. The two alpine lakes sit in old-growth pine and rhododendron forest at around 3,500 metres altitude, with wooden boardwalks running along the shorelines. A park shuttle bus takes you between the entrance, the two lakes, and the major viewpoints; you walk the boardwalks at each stop.
A full day is enough. Conditions are best from May through October. The shuttle is mandatory — you cannot drive your own vehicle inside the park — and the entrance fee is steep by Chinese standards, but the boardwalks are well kept and the forest is among the more atmospheric in the region.