The key oasis towns , watered by rainfall from the mountains , were Kashgar , Marin , Niya , Yarkand , and Khotan ( Hetian ) to the south , Kuqa and Turpan in the north , and Loulan and Dunhuang in the east .
The key oasis towns , watered by rainfall from the mountains , were Kashgar , Marin , Niya , Yarkand , and Khotan to the south , Kuqa and Turpan in the north , and Loulan and Dunhuang in the east .