Although the Philip Johnson Glass House tends to garner much of the fanfare in the modernist glass house department, Ludwig Mies van der Rohe’s Farnsworth House (built in 1951 but conceived of a few years earlier) actually served as the inspiration for Johnson’s home, which was completed two years prior in 1949. Apparently, the German-born architect was none too pleased about this, although that didn’t stop him from collaborating with Johnson on Manhattan’s iconic Seagram Building (1958). Erected on a sylvan 62-acre estate near Plano, Ill., Mies van der Rohe explained the concept behind the 1,5000-square-foot vacation home that blends seamlessly into its natural surroundings: “Nature, too, shall live its own life. We must beware not to disrupt it with the color of our houses and interior fittings. Yet we should attempt to bring nature, houses, and human beings together into a higher unity.” Designated as a National Historic Landmark in 2006, the Farnsworth House is now owned by National Trust for Historic Preservation and open for public tours.