China: Western gate and tower at Jiayuguan Fort, Gansu Province

Jiayuguan, the ‘First and Greatest Pass under Heaven’, was completed in 1372 on the orders of Zhu Yuanzhang, the first Ming Emperor (1368-98), to mark the end of the Ming Great Wall. It was also the very limits of Chinese civilisation, and the beginnings of the outer ‘barbarian’ lands. For centuries the fort was not just of strategic importance to Han Chinese, but of cultural significance as well. This was the last civilised place before the outer darkness, those proceeding beyond, whether disgraced officials or criminals, faced a life of exile among nomadic strangers. Jiayuguan or Jiayu Pass (literally 'Excellent Valley Pass') is the first pass at the west end of the Great Wall of China, near the city of Jiayuguan in Gansu province. (Photo by: Pictures From History/Universal Images Group via Getty Images)