Alhambra, Spain

The Alhambra stands as Europe's finest Islamic architecture, a fortress-palace built by Granada's Moorish rulers from 1238 to 1358. Its intricate stucco carvings, geometric tile work, and courtyard fountains impressed Washington Irving as "a dream in marble." Spain's most-visited monument, it draws 2.7 million visitors annually—tickets sell out months ahead. The decorative detail surpasses that at Hohenzollern Castle, ranked #8, where 19th-century gothic revival cannot match the Alhambra's precision.