函谷关
Hangu Pass or Hanguguan is a pass separating the upper Yellow River and Wei valleys—the cradle of Chinese civilization and seat of its longtime capital Xi'an—from the fertile North China Plain. It lies on the south bank of the Yellow River just east of its eastward bend out of the Ordos Loop at Tong Pass in Shaanxi. It was the site of many battles during the Warring States and early imperial eras, when it was the chokepoint shielding Qin, Guanzhong, or Luoyang from outside attack. Today, the term Hangu Pass refers to two locations: firstly, to a museum park including a reconstruction of the gate in Lingbao county, Sanmenxia city, Henan and secondly, to the archaeological site of the gate in Xin’an county, Luoyang city, Henan. In 2014, the archeological site was recognized by UNESCO as part of the “” World Heritage Site.