渭南市, Italy
Tongguan, or Tong Pass, was a former mountain pass and fortress located south of the confluence of the Wei and Yellow Rivers, in today's Tongguan County, Weinan, Shaanxi, China. It was an important chokepoint, protecting Xi'an and the surrounding Guanzhong region from the North China Plain. Tong Pas
s was built in 196 AD by the warlord Cao Cao during the late Eastern Han dynasty. The fortress was the seat of Tongguan County, but was demolished in the 1950s to make way for the Sanmenxia Dam and reservoir.
Listen to the audio guide for Tong Pass Free on WIP — starts by itself when you arrive, even with the screen off