The Library of Congress is truly a spectacular building. The interior is extraordinary as you can tell from these pictures. It is also an actual working research library.
I remember using it for a paper Freshman year in college. My subject was the War of 1812 and the burning of Washington. I got to read books that were published in the early 1820s. Then there was the time I was allowed up in the stacks of the library itself. I did my research and then did a little exploring to see what else was around the section I was in. It was a very interesting afternoon. I have to assume now you're no longer allowed up there.