Fodor's Expert Review Palácio da Bolsa
Formerly Porto's stock exchange, Palácio da Bolsa is one of the city's most breathtaking historical buildings. Guided tours leaving every half hour are the only way to see the interior of this masterpiece of 19th-century Portuguese architecture, so if you're only in Porto for one day, it's wise to book your tour in the morning for an afternoon time slot. The grand Moorish-style ballroom, with its octagonal dome and ornate arches, is the most memorable chamber. A high-end restaurant, O Comercial, serves European dishes in a suitably grand space with high ceilings and elaborate chandeliers.