The National Mall & Its Monuments (World/US&C)
I think pictures say it best...
I've been to the National Mall a few times and still have not seen it all. There is too much to describe, but of note is that in 1791, Washington DC was the first planned national capital in the world. The U.S. Capitol is at one end of "the mall" and the Lincoln Memorial at the other end with the Washington Monument in the middle.