Library of Congress

The Library of Congress is the largest library ever assembled - more than 170 million items in some 470 languages, from cuneiform tablets to born-digital archives - and its Thomas Jefferson Building of 1897 is the most beautiful room America ever built for reading. The Great Hall makes the argument on entry: stained-glass skylights, marble staircases, mosaics and murals by dozens of artists, gold leaf laid on with Gilded Age conviction. From the overlook, the Main Reading Room spreads its dome over concentric desks of scholars beneath statues of the disciplines - working theatre, not museum piece, since anyone over sixteen can register for a reader card and take a desk. The treasures rotate through the galleries: a Gutenberg Bible - one of the few perfect vellum copies surviving - holds permanent court, alongside Jefferson's own library, reassembled ring by ring after he sold it to restart the collection in 1815.

What you actually see

• The Great Hall - mosaics, murals and gold under stained-glass skylights.
• The Main Reading Room overlook - the working dome from above.
• The Gutenberg Bible - the perfect vellum copy in permanent display.
• Jefferson's library - the founding collection reassembled in its ring.

When to go

Open Tuesday to Saturday with free timed-entry passes booked online - same-week passes usually survive except in cherry-blossom spring and summer holiday weeks. Late-afternoon slots are quietest; Thursday evenings extend the hours.

Honest expectations

You must book the free pass ahead - walk-ups without one are turned away when slots are gone - and security screening queues like an airport at peak times. The Main Reading Room is overlook-only unless you register for the reader card, which takes an hour and is worth every minute for bookish visitors.

Nearby

The US Capitol, the Supreme Court building and the National Mall's museums.