I think that the most beautiful building in Washington DC is the Library of Congress. The purpose of my visit there today was to get some instruction on architectural photography in a workshop. During most of the visit, the hordes of tourists made photography a challenge, but as closing time approached I was able to get a few shots I liked.
This is a shot of the Great Hall taken from the north mezzanine looking south. The extras include two shots of the Reading Room. It is closed to the public, but there is a balcony observation area. Unfortunately, it is enclosed in glass, with lots of fingerprints. The last extra was taken from the west mezzanine looking across to the steps that lead to the Reading Room observation area.
More information about the Library can be found HERE, along with a very good shot of the Reading Room.