This is the Great Hall inside the Thomas Jefferson Building of the Library of Congress, Washington DC. It's a pretty impressive space. Kathy and I visited it on a whim, walking over from the US Capitol Building after taking the tour there. As you can see it was packed with tourists. Next time I want to be there when they open. No tripods allowed so this was taken by balancing the camera on the marble railing that surrounds the perimeter of the hall. Built in 1890, this building is one of the most beautiful places I've seen in DC.