Sure, you can pay for a tour, but if you're up for a free adventure at your own pace and leisure, downtown Chicago is the gift that keeps on giving. This is one of a million possible routes, but it begins and ends with two SC favorites.
Start at the Monadnock Building (53 W. Jackson Blvd.) in the South Loop. Pause a moment to read this essay on why it represents one of the most important achievements in modern architectural history. Grab a cup of coffee or tea from the coffee shop, Intelligentsia, on the building’s north side; and, if you're inclined, soak in the dimly lit elegance of the building’s ground floor and browse its shops, including a haberdashery, a shoe-repair service, a hat store, and a tobacconist.
On Jackson Street, the building’s northern border, head west two blocks to LaSalle. The Chicago Board of Trade, a classic of the Art Deco style, will be to your left, although your view of it will be blocked until you head north on LaSalle. Walk up to the corner of LaSalle and Quincy, turn around, look up, and take in one of the most magnificent views in the city, as the Board of Trade building looms over you to the south and the Willis (formerly Sears) Tower rises off to the west.
Keep going north and you’ll see the Rookery Building on the right. (The revolving-door entrance is a bit before Adams.) Step inside and be awed by the lobby, re-designed by Frank Lloyd Wright in 1905 and subsequently re-designed and restored a couple of times. Head east on Adams for two blocks and you’ll come to the Marquette Building. Note the massive Flamingo sculpture in the plaza to your right. Continue east on Adams another block and you’ll be at State, the city’s unofficial main street.
Now head north and you’re a few blocks from one of the city’s great theaters, the Gene Siskel Film Center. (The famous Chicago Theater is right across the street.) It’s well worth planning ahead and watching a movie there. Along the way, you’ll see some of the city’s most notable landmarks, including Louis Sullivan’s Carson, Pirie, Scott building (between Monroe and Madison streets) and the Reliance Building at 32 N. State. A brief detour west of State at Monroe will take you to the Inland Steel Building, a modernist masterpiece of glass and steel
Along your walk up State, the iconic, corncob-like Marina City towers will be looming off in the distance. If you have time before or after the movie, keep going north two blocks and you'll be at the entrance to Chicago’s Riverwalk, a pleasant way to get more exercise and take in even more spectacular views of the towers.