Ilha de Moçambique: Fortaleza de São Sebastião
The Fortaleza de São Sebastião is the grandest of all European forts in Sub-Saharan Africa. It was built by the Portuguese between 1546 and 1583 as a response to the Ottoman threat. Its walls reach a height of up to 20 meters. It was never captured by foreign armies in spite of some serious attempts. The Portuguese built small fortifications here as early as 1507.