A contender for the title ‘China’s Greatest View’ has to be the panorama of jagged peaks, boulder-strewn snowfields and waterfalls surrounding Tian Chi Hu, a spectacular crater lake on the border of North Korea. Filling a windswept caldera, the lake’s deep-cobalt-blue waters form the centrepiece of the Changbai Shan Nature Reserve, a park visited by large numbers of Chinese but surprisingly few foreigners. In summer, thousands of walkers every day hike up the flight of 1,000 steps to the viewing platform overlooking the lake.