In Yan’an, high on China's northwest Loess Plateau, where per capita water availability is less than a third of the national average, how can the city make every drop count? The key to creating a thriving urban oasis lies 16 meters underground, beneath an ecological park. Ninety years after the victory of the Central Red Army's Long March, Yan'an is forging a greener future. Join CGTN host Wang Guan to find out how a miracle took shape!