Luxemburg - Europe's "Little Fortress" (163/418)

Because of its strategic position, Luxembourg was from the 16th century until 1867, when it became neutral, one of Europe's greatest fortresses. Repeatedly fortified as it passed from one great European power to another (the House of Burgundy, the Habsburgs, the French and Spanish Kings, and the Holy Roman Emperors), its fortifications were, until their partial dismantlement, an epitome of military architecture spanning several centuries.