Alcazaba of Málaga

Rising above the port of Málaga, the Alcazaba was built from about 1057 by the Hammudid dynasty, reusing Roman columns from the theatre at its foot and doubling as palace and citadel behind concentric walls and zigzag gates. During the Reconquista's final push, the Catholic Monarchs besieged Málaga for over three months in 1487; when the exhausted, starving city surrendered, Ferdinand and Isabella enslaved much of the population as punishment for their resistance—one of the harshest reprisals of the war. The higher Gibralfaro castle, linked by a covered rampart, held out longest. From its towers you still look down onto a Roman theatre carved 1,500 years earlier.