TheMart, as the Merchandise Mart is now called, is the world’s largest commercial building. Spanning two city blocks, the 1931 behemoth has its own zip code and gives most of its copious space to wholesale showrooms for home furnishing and design professionals. Many are on floors 6, 14, 15 and 16, if you want to browse. The first two floors are mall-like with eateries and clothing shops. At night, theMart becomes a psychedelic canvas for video art projected on the exterior.

　　The eye candy is called Art on theMart (www.artonthemart.com), and it’s a very cool public light show done with 34 projectors set up along the Riverwalk. Times vary, but it happens for two hours sometime between 5pm and 9pm Wednesday through Sunday (except no show during January and February). The website has the schedule. The best views are from the Riverwalk.

　　Also outdoors on theMart’s river side is a collection of heads on poles that rise up like giant Pez dispensers. This is the Merchant’s Hall of Fame, and the creepy busts depict famous local retailers such as Marshall Field and Frank Woolworth.