Castle of Alegrete

Portugal, Portugal

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Castelo de Alegrete near Portalegre, Portugal, was first captured from the Moors around 1148 by King Afonso I and formally incorporated into Portuguese territory via the 1267 Treaty of Badajoz between Afonso III and Castile's Alfonso X.

Rebuilt extensively in the late 13th-early 14th centuries under King Dinis—who granted a charter in 1319—it served as a vital Alto Alentejo frontier fortress in the Serra de São Mamede, hosting Nuno Álvares Pereira's forces in 1384 and sheltering royals during border conflicts.

Its irregular Gothic walls, towers, and later 16th-17th century bastions adapted for artillery endured sieges like the 1662 Spanish assault, now standing as evocative ruins symbolizing centuries of defensive warfare.