The Real Gabinete Português de Leitura — the Royal Portuguese Reading Room — is one of the great library interiors of the world. The main reading room is a four-storey hall of Portuguese stone, carved wood, and stained glass in the neo-Manueline style, with wrought-iron balconies on three upper levels and skylights flooding the room with natural light. The effect is somewhere between a cathedral and a jewel box.
The library holds over 350,000 volumes, including rare 16th-century editions, manuscripts, and the largest collection of Portuguese literature outside Lisbon. Admission is free during regular library hours. The building is a short walk from Centro's main streets and often overlooked by visitors focused on the beach zones — one of Rio's genuine hidden gems. Photography inside the reading room is allowed.