When we stayed in Turpan , we visited Jiaohe an ancient city built on a mesa surrounded by cliffs. There were only 2 ways to up the cliff so the ancient settlers had great protection. In Turpan we visited an ancient irrigation system. They still grow wonderful grapes in there. We traveled to Dunhuang by “soft sleeper train” which was a little crowded. It was just as well that it was night time because the scenery didn’t change much.