This splendid neoclassical monument (built from 1842 to 1910) honours Porto’s past and present money merchants. Just past the entrance is the glass-domed Pátio das Nações (Hall of Nations), where the exchange once operated. But this pales in comparison with rooms deeper inside; to visit these, join one of the half-hour guided tours, which set off every 30 minutes.
The highlight is a stupendous ballroom known as the Salão Árabe (Arabian Hall), with stucco walls that have been teased into complex Moorish designs, then gilded with some 18kg of gold.