Fort São Sebastião

Fort São Sebastião is a rectangular stone structure with thick coral walls standing at the northern end of Stone Town. Inside are former barracks, storage rooms, and period cannons that offer glimpses of life under Portuguese rule.

Italian architect Giovanni Battista Cairati designed this military stronghold in 1558, though construction took fifty years to complete. Portugal built the fort to control important trade routes eastward and establish dominance along the African coast.

The fort blends European military design with local building methods, using coral stone quarried nearby for its walls. Visitors walking through can see how two architectural traditions came together in this stone structure.

Guided tours provide access to interior sections including former barracks and storage areas with preserved cannons on display. Visitors should wear comfortable shoes since exploring the stone structure involves uneven flooring and narrow stairways.

The Zamani Project created detailed 3D laser scans of the entire fortress in 2013, capturing every corner of this oldest complete fort south of the Sahara. This digital record allows future researchers to study the structure with precision down to fine architectural details.