Also called Yarkhoto, Jiaohe was established by the ancient Jushi kingdom as a garrison town in the 2nd century BC. It’s one of the world’s largest (6500 residents once lived here), oldest (1600 years old) and best-preserved ancient cities, inspiring with its scale, setting and palpable historical atmosphere. Get an overview of the site at the central governor’s complex, then continue along the main road past a large monastery to a 'stupa grove' with a 10m-tall pagoda surrounded by 100 smaller pagoda bases.
While far busier than the similar ruins at Gaochang, these are definitely the most impressive of the two, mainly due to the sheer number of surviving structures and the dramatic location, on a hillside with wide views in all directions. The ruins are 10km west of Turpan. There's no public transport; a taxi (¥30) takes 20 minutes, or you can cycle.