Chicago's architecture is one of the city's main claims to fame, and a quick swing through this center will help you understand why. Run by the well-regarded Chicago Architecture Foundation, it's conveniently located across the street from the Art Institute. Still trying to figure out the difference between Prairie School and postmodern? Stop in here for a quick lesson. Exhibits include a scale model of downtown Chicago, profiles of the people and buildings that shaped the city's look, and a searchable database with pictures and information on many of Chicago's best-known skyscrapers. "Architecture ambassadors" are on hand to provide information on tours run by the foundation. Two galleries feature changing exhibits about ongoing Chicago design projects -- so you can see firsthand how local architecture continues to evolve. There's also an excellent gift shop filled with architecture-focused books, decorative accessories, and gifts. Allow a half-hour, more if you want to browse in the store.