Gothic architecture emerged in France in the 12th century. This architectural style revolutionized church construction, creating cathedrals that soared skywards. But where did the knowledge and technology for building these monuments come from? Light floods the interiors of Gothic cathedrals, which have colorful windows instead of solid walls. All told, the windows of Chartres Cathedral in France would cover an area larger than a football pitch. Another impressive example is St. Stephen's Cathedral in Vienna, Austria, the federal capital's iconic landmark.