The stream in front of Tiananmen is called Outer Golden River, Wai jinshuihe in Chinese, with seven marble bridges spanning over it. Of these seven marble, historical records every one have their function:

• Imperial Bridg: the middle one was for the exclusive use of the emperor and was accordingly called Yuluqiao (imperial Bridge).
• Royals Bridges: The bridges flanking it on either side were meant for the members of the royal family land were therefore called Wanggongqiao (Royals Bridges).
• Ministerial Bridges: Farther away on each side of the two were bridges for officials ranking above the third order and were named Pingjiqiao(Ministerial Bridges).
• Common Bridges: The remaining two bridges were for the use by the retinue below the third order and were called Gongshengqiao (Common Bridges). They are the one in front of the supreme Ancestral Temple to the east and the one in front of the Altar of Land and Grain to the west.

Beijing Tour Routes covers Tiananmen Square:

Photo of Tiananmen Square