One of the largest city squares in the world, American students will probably know Tiananmen Square from the infamous photograph of a Chinese student blocking the progress of an army tank during the huge pro-Democracy movement that happened in 1989. A massive concrete space of monuments, halls and even China's National Museum, it is also the place to see China's flag raised ceremonially every morning and lowered every evening. Because it has long been a site of mass gathering and protest, there is both video and police surveillance, although there is no need to worry if you've just come to see the sights.
At the square's center, there is Monument to the People's Heroes (38 meters/124 feet high) and Mao Zedong Mausoleum, while at the south end is the Tiananmen Tower, which costs a little over $2 US for the excellent view at its peak. The National People's Congress meets at the west end in the Great Hall of the People.
For a great example of how a city can do self-promotion right by creating an ample space for it to commemorate what the country stands for, both now and historically, bring your curiosity to Tiananmen Square.
Note:Tiananmen Square is easily reached from a number of bus and subway lines, lying just south of the Forbidden City.