New York Times: It is an improbable journey that begins on the highest peaks of the Tianshan Mountains, where glacial snowmelt descends across one of the worlds most arid landscapes to reach the lush oasis communities of this ancient Silk Road outpost. Powered by gravity, the water pure and cold makes the entire voyage underground, traveling through scores of subterranean channels, some of them 15 miles long and 100 feet deep, that were built 2,000 years ago by the pastoralists who settled this inhospitable...