The Forte dos Reis Magos stands on a reef at the very tip of a peninsula where the Potengi River meets the Atlantic, guarding the entrance to Natal's harbor. It is a star-shaped fort built in the late 16th and early 17th centuries, and it is Natal's oldest and most recognizable landmark. Walking out to it along the causeway at low tide, with the surf breaking on both sides, is one of the better approaches to any fort in Brazil.
The interior is modest but the views are outstanding — the river mouth, the city skyline, and the ocean stretching north. The fort is still owned by the Brazilian army and access is through a short walk or bus ride north of the city center. Allow about an hour. There is a small museum inside with exhibits on the fort's history and the region's colonial past.