Introduction to the Zhanyun Archway: The name of Xidan comes from an archway, and the title of the archway is "Zhanyun". There is also an archway at the intersection of Dongdan Road in Dongcheng District, named "Jiu Ri". Because they are both single archways and face each other from east to west, they are commonly known as Xidan Archway and Dongdan Archway, or Xidan and Dongdan Archway for short.