Résumé en anglais
The approach to the reading of the materials and structures of the fortress of São Sebastião in Ilha de Moçambique must be accompanied by knowledge of the stages that marked its building. This architecture should be fully examined, and the studies, prior to the 1980s, of its transformations should be resumed to understand its history and its current physical structure. From my survey it seemed that the idea of designing the fortifications as a set of flexible rather than brittle materials was seriously considered in the seventeenth century transformations at the bulwarks São Gabriel to the southwest and Santa Bárbara to the southeast. This hypothesis, obviously, should be verified by tests and stratigraphic surveys.