Fortaleza da Nossa Senhora da Conceição
Though it's on not-so-scenic grounds and is not very well-maintained, this historic late 18th-century Portuguese fort, with its stout stone walls and cannons reminiscent of Cape Town’s castle, is worth a visit. It's best to hire a guide, as site information is very sketchy. You'll find it at the bottom of Avenue Samora Machel, near the sea.