Castle of Castro Marim

Castle of Castro Marim is a fortress built on a hilltop with cylindrical towers, thick stone walls, and defensive structures overlooking the Guadiana River and salt marshes. The complex includes an archaeological museum and exhibits about medieval military architecture that show how such fortifications were designed and used.

King Afonso III built the fortress in 1277 to defend Portuguese lands against Islamic forces, incorporating earlier Roman and Moorish fortification elements. Afterward it passed under the control of military orders and served as a key defensive position for centuries along the border.

The Igreja de Santiago church stands within the castle grounds, built by the Order of Santiago after taking control in 1334. The presence of this religious building within the fortifications shows how spiritual authority and military defense were intertwined in medieval times.

The castle is open daily for visitors to explore the archaeological museum, walk along the battlements, and see exhibits about medieval military architecture. The layout allows easy movement through different levels of the fortress with various viewpoints over the surrounding landscape.

The fortress forms part of a dual defense system with Forte de Sao Sebastiao, together controlling the salt pans and Spanish border from strategic positions. This paired arrangement shows how deliberately the Portuguese organized their defenses across this frontier landscape.

Location: Castro Marim

GPS coordinates: 37.21852,-7.44194

Latest update: December 8, 2025 21:00