唐天坛遗址

This guide to the Tang Heaven Altar site in Xi'an opens with a question: would you believe an emperor's whole right to rule rested on a ceremony performed at dawn atop this earthen mound? It traces the altar from its founding by a Sui emperor in 590 through the Tang dynasty, when more than twenty rulers climbed its four rammed-earth tiers to prove who was truly meant to reign. Emperor Taizong climbed it three times, and Wu Zetian, the only woman ever to rule China as emperor in her own right, climbed it twice.