August Perret's Le Havre, France

When French architect August Perret was invited to remake the bombed-out core of La Havre (180 km northwest of Paris) after the Second World War, he created what is now a UNESCO World Heritage site. The open-plan framework of his public housing allows placement of non-structural interior partitions wherever desired-permitting quick, easy renovation that in turn allowed residents to age in place by changing the layout whenever they made lifestyle transitions (from couple to young family to empty-nesters). The façade was a kit of parts: window, glass-brick wall for translucent bathroom privacy, or balcony insert. The raw concrete structure, left exposed to view, was decoratively treated. Perret's work left a lasting influence on interior design, architecture and city planning. Tourists can stay at the Ibis Hotel, a lovingly preserved Perret building with the original late-Forties furnishings and plumbing fixtures; and visit Perret's own apartment, now a museum, featuring his ingenious custom furniture and even his wife's wardrobe.