When I tell architecture students that the so-called Vanna Venturi house, which her son American architecture Robert Ventuti designed in 1964 in the Philadelphia’s suburb of Chesnut Hill, is one of the most important residential projects of the 20th century, they often seem surprised and questionable. After all, it is not as magnificent as Villa Savoye; not as photogenic as the Farnsworth House; not as poetic as the Salk Institute; and not as prolific as Villa Tugendhat. Now that the house is on the market for sale, it is time to look at the house that was the lab for Venturi and his partner Denise Scott Brown's philosophy. The house has marked the turning point in American architecture, a changing of attitude, a rejection of European modernism, and a search for an inspiration in the past. In fact, while building the house, Venturi published his anti-Modernist polemic ‘Complexity and Contradiction in Architecture,’ in which he outlined his own architectural ideas. In the house, which is considered one of the earliest manifestations of Posemodernist architecture in the US, Robert Venturi lived his 1967 marriage to Denise Scott Brown. Vanna Venturi lived there until 1973, when she moved to a nursing home, and sold it to Thomas P. Hughes, an historian, author, and university professor, and his wife, Agatha, an editor and artist who have put it on the market now.