Castle of Campo Maior

Portugal , Portugal

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Castle of Campo Maior in Campo Maior, Portugal, was first conquered from the Moors in 1230 by Leonese forces, recaptured multiple times, and definitively integrated into Portugal in 1297 via the Treaty of Alcanices, prompting King Dinis to rebuild it around 1310 as a key Alentejo frontier defense against Spain.

Expanded in the late 15th-16th centuries under Kings John II and Manuel I with new urban walls, it was radically modernized after 1640 during the Restoration War by engineers like João Cosmander and Nicolau de Langres, forming a ten-sided bastioned fortress with bulwarks, ravelins, barracks, stables, and a powder magazine rebuilt in 1735.

Retaining two of six original rectangular towers—one with a Renaissance window—within trapezoidal medieval walls and an elliptical village enclosure with seven towers, this National Monument since 1911 exemplifies layered Gothic-to-Vauban defenses overlooking the border plain.