Xi'an, capital of the Shaanxi province is one of the most polluted cities. Yet amid this foggy air, Xi'an hides the "Eight Wonder of the World", the Terracotta Warriors. Bing Ma Yong, as they call it is the tomb of the first emperor, Shih Huang Ti. Each statue is said to be different, and if you look further into its history, you'll understand. Accordingly, each potter had to write their name of their statue and if the emperor thinks it's subpar, the potter wont have to worry about making ends meet anymore. 

Besides the Terracotta Warriors, Xi'an has the most majestic and complete city wall that encircles the entire city. And within this wall lies the Drum Tower and Bell Tower that is a must see.