At the heart of the Jewish Cultural Quarter stands the majestic Portuguese Synagogue. The building is still used for religious services, but it is also open to the public. It hosts frequent candlelight concerts. Hundreds of candles illuminate the perfectly intact 17th-century interior. Visitors to the smaller buildings in the complex will find treasure chambers containing a unique collection of ceremonial objects made of silver, gold, brocade, and silk. The world’s oldest functioning Jewish library is also here: Ets Haim Livraria Montezinos, which is on UNESCO’s World Heritage List.