Changbaishan — the Ever-White Mountain — is a dormant volcano straddling the border of Jilin province and North Korea, and the most mythical landscape in China's northeast. At its summit, in a caldera left by an eruption so vast it is studied worldwide, sits Heaven Lake: China's deepest lake, an unnervingly blue bowl of meltwater at over two thousand meters. Manchus trace their ancestors here; Koreans hold the same mountain sacred. Around the crater falls a complete ladder of ecosystems — primeval forest, hot springs, waterfalls, alpine meadows — managed as a UNESCO biosphere reserve with separate north and west visitor zones. Weather decides everything, and the lake famously reveals itself to only some of those who climb to it.
