While the exterior of the Library of Congress isn't one of Washington's most memorable building, the inside is certainly the most beautiful library you'll ever find in the United States. The library is the oldest federal institution, dating back to 1800, and currently the collection has more than 23,000,000 books.
As a tourist visiting without a reader card, you'll be hard pressed to see any of the Library's huge collection, but in one area you can ascend a set of stars to see one of the famous circular reading rooms.
The reading rooms gained pop culture fame with a notable scene in the Oscar-winning film All The President's Men. Robert Redford and Dustin Hoffman (as Bob Woodward and Carl Bernstein) go to the reading room to sort through receipts after being told to "follow the money" by their informant Deep Throat.
The camera pulls back to reveal the whole room from above and simultaneously shows the small nature of the two reporters researching the Watergate story and demonstrating the size and scope of the American government.
Here's the brief All The President's Men clip that features the Library.
The iconic scene was featured in the Simpsons in one of the series' best episodes, Sideshow Bob Roberts. Lisa is researching the election results from the Springfield mayoral election and the camera pulls back in a similar fashion to reveal that Springfield Library's reading room rivals that of the Library of Congress.
Thinking about it, I believe I saw the Simpsons episode well before All the President's Men and so it was probably years before I really understood this joke.