As the oldest cultural institution in the US, the largest library in the world and housed in the historic Capitol Hill estate, a visit to the Library of Congress is essential when in Washington DC. Formed by three buildings, the Jefferson Building being the most famous, it currently serves as a research institution and as repository to some of the most important documents in history, as well as maps, photographs, sheet music and of course millions and millions of books, including rare editions. Although access to many items is restricted, there are exhibitions of The Library of Congress’ own collections at the Jefferson building and many treasured items are on display. Considered one of the most beautiful public buildings in America, the Jefferson Building itself is worth visiting, with its magnificent Great Hall, marble columns, the astonishing staircase, the mosaics and paintings and the main Reading Room.