The small coral island in the Mozambique Channel, just 4 kilometres from the mainland, is a fortified city island that was once a major trading post between Africa and Asia. The fort, constructed by the Portuguese in the mid-16th century, saw the trading of slaves, spices and gold.

The Chapel of Nossa Senhora de Baluarte, located on the eastern tip of the island, is considered to be the oldest European building in the southern hemisphere. Mozambique Island (Ilha de Moçambique) is a UNESCO World Heritage Site.

The Zamani Project team spatially documented the Fort of São Sebastião during two field campaigns in 2009.

Similar sites:
Elmina Castle (Elmina, Ghana), Fort Saint Jago (Elmina, Ghana), Fort Saint Sebastian (Shama, Ghana), Cape Coast Castle (Cape Coast, Ghana), Fort Saint Anthony (Axim, Ghana), Castle of Good Hope (Cape Town, South Africa),  Fort d'Estress (Ile de Gorée), Bunce Island Fort (Bunce Island, Sierra Leone)