The greatest gems of French architecture are represented at the City of Architecture and Heritage, which occupies the east wing of the Palais de Chaillot. Reopened in 2007 after an €84 million renovation, the former French Monuments Museum contains some 350 plaster-cast reproductions spread out over 86,000 square feet. While it may seem odd to see a collection comprised entirely of copies, these are no ordinary ones: they include partial facades from some of the most important Gothic churches, a gallery of frescoes and windows (among them a stained-glass stunner from the famous Chartres cathedral), plus an assembly of gargoyles practically leaping off the back wall of the soaring first-floor gallery. Video monitors with joysticks allow a 360-degree view of some of the grandest cathedrals. The upper-floor gallery is devoted to architecture since 1851, with a life-size replica of a postwar apartment in Marseille designed by the urban-planning pioneer Le Corbusier. It's well worth picking up the free English audiovisual guide. When you're ready for a break, the museum's small café offers a great view of the Eiffel Tower.