Occupying an enormous 2339 sq km and one of China's largest freshwater lakes, Hulun Lake, called Dalai Nuur (Ocean Lake) in Mongolian, unexpectedly pops out of the grasslands like a colossal inland sea. Summer and early autumn are the best seasons to visit for the full colours of the grasslands. The lake is 47km southeast of Manzhouli; you'll need to get here by taxi (around ¥200 return from town).