All the world's great cities have tour companies that, for a small fee, show tourists around. For those new to Chicago, a half-day motor coach or on-and-off "trolley" tour is a perfect way to get oriented and to efficiently see those things that must be seen. But Chicago, the greatest of great cities, also offers highly specialized tours that highlight what makes Chicago truly different.

From the dozens of specialized Chicago tours out there, here's a sampling.

Wright's Robie House
In Chicago, architect Frank Lloyd Wright found his mentor, Louis Sullivan, and launched his career. Take a guided walk through Chicago's prime example of the man's “Prairie style” vision. Free bonus: The University of Chicago campus is right there.

Wrigley Field  
Explore the innards of this 1914 ballpark where Babe Ruth called his shot, Ernie Banks chirped "let's play 2" and the vines swallow baseballs.

Chicago Pizza
Chicago debates pizza the way Philly debates cheese steaks and Washington debates appropriations. Deep dish, thin crust or hot out of a wood-burning oven, here's a tasty way to understand how Chicago satisfies lovers of these Italian (and sometimes not-so-Italian) pies.

Cupcake  
Is this just another food fad, or are lines outside cupcake bakeries here to stay? Does it even matter? The hottest trend in baked goodies gets its own red velvet treatment on this Chicago tour, where licking the frosting is acceptable behavior for grownups, too.

Chicago Rocks
The Rock and Roll Hall of Fame might be in Cleveland, but especially in the 1970s and '80s Chicago was a major incubator of alternative rock. Want to see where the Smashing Pumpkins became a smash? Where Cobain met Courtney? Ride along with ex-rocker Phil Rockrohr.

Printer's Row Red-Light District  
Books and bordellos: Well, it is, frankly, an exploration of architecture and of tales from long ago. Neither printers nor prostitutes work there (much) anymore. Even so, if you're hauling kids, fair warning: This one is R-rated.

Helicopter
Some places look better from a distance. You may debate whether Chicago looks better from ground level than from 2,000 feet while a propeller goes wadda-wadda-wadda over your head, but as a photo op, this Chicago tour is hard to beat.

Chicago Architecture Foundation River Cruise  
A number of tours sail the Chicago River and point out the sights, and they're all fine and fun. But for serious buffs of architecture, this one, aboard Chicago's First Lady, leads all in consistent credibility.

Untouchable  
Revisit scenes of gangster crimes and revel in stories about Al Capone and "Bugs" Moran and John Dillinger and Dion O'Banion -- and the FBI, of course -- on this fun bus ride back into the 1920s and 1930s.

Near North Food Tasting & Cultural Walking
Food, ethnic diversity and architecture rank high in Chicago. This one, which strolls about some of Chicago's most fascinating blocks, tickles them all.

Chicago Hauntings  
Ghost tours are familiar these days, and not just in big cities. Several operators offer variations in Chicago, but author/guide Ursula Bielski takes this stuff really seriously. This gives her tours an extra creepiness. And isn't that the whole idea?

Bobby's Tike Hike
Being mostly flat, Chicago is good for 2-wheelers -- and several variations are offered under the Bobby's brand. This one, though, specifically targets families with kids 10 and under, and does Lincoln Park Zoo's Children's Zoo, the lakefront and other G-rated places.

Segway Fireworks
The first trick is overcoming your resistance to these 2-wheeled electric conveyances. Then strap on your helmets and glide through Grant Park and Buckingham Fountain to the Museum Campus -- all aglow -- and watch the show. Seasonal, on Wednesdays and Saturdays.

26.2 Miles of Chicago
Missed the annual Chicago marathon but don't want to miss marathoning through Chicago? Here's an option. And there are options within the option: You can split the run into 4 parts over 4 days. Water, companion runner/guide and goodies provided.

Chicago Beer Experience
It's the ideal chaser after a 26.2 mile experience. Visit several Chicago North Side establishments with like-minded visitors and thirsty locals, see parts of Chicago that other tours skip and get a taste of history along with a taste of multiple malt beverages.

Chicago-based travel writer Alan Solomon has never stopped touring his hometown -- and discovering great stuff.