The Ilha Fiscal is a small island in Guanabara Bay, 800 metres from the shore, topped by an extraordinary neo-Gothic palace that looks like something from a fairy tale — green spires, Gothic arches, and ornate stonework rising from the water. Built in 1889 as a customs inspection house, it never actually served that purpose: within weeks of its completion, the Empire was overthrown.
The palace now houses a naval museum and is open for guided tours at weekends, departing by boat from the Espaço Cultural da Marinha near Praça XV. The tour covers the island's history, the imperial interiors, and the story of the last ball. The building is visible from the Praça XV waterfront and from the Niterói ferry; on a sunny day the green Gothic spires against the blue bay are startlingly beautiful.