The Chicago Architecture Foundation’s elevated train tour offers perspectives, like this view of the neo-Gothic Fisher Building, not available from the streeet (Joe Yonan/The Washington Post)

I’m on the “L,” Chicago’s elevated train, rumbling past building after building, 20 feet off the ground, when a little voice in my left ear says, “Okay, just before we turn the corner, be on the lookout for the third shell medallion from the end, and tell me what you see.”

I’m on the lookout indeed, and as the train starts to hug the corner around the LeMoyne Building, I watch the lineup of ornaments on its exterior. And then I see it: The shell above one of the exterior pillars is upside-down. “Now you have to wonder,” the voice in my ear continues. “Did they not notice, or was it a joke for the train people? I’m going with a joke.”

The voice belongs to Lynn Hensel, a docent on this Chicago Architecture Foundation tour, who’s speaking to me through a little earpiece connected to her own microphone and transmitter. Of the 85 tours the foundation leads on foot, by boat and by Segway, this is one of the newest. And I’m taking it because I’m intrigued by the idea of getting a unique perspective on the city’s boisterous architecture from a vantage point offered by what less urban-minded folks might consider just a noisy eyesore. In the so-called City of Big Shoulders, this is like crawling around at knee height.

Hensel weaves her views on building motifs, materials and styles — from the classic Chicago school to neoclassical, modernist and postmodern — together with stories of the L’s development from a series of disparate lines into a unified system in the late 1890s. At the center of that effort was Charles Tyson Yerkes, who apparently strong-armed property owners into giving their permission for the crucial center loop to be built. His tactics involved bribes and the use of “vamps” who seduced and then blackmailed. “By hook or by crook, he got the job done,” Hensel said with a smile.

The tour focus, though, is on the buildings. And what buildings! Chicago’s forward-thinking architecture no doubt stems from the city’s near-destruction in the Great Fire of 1871, and Hensel shows us one stunning structure after another, sometimes closer than you could get any other way short of moving in. When we take a train past the Board of Insurance Building, she tells us that one corner of the building had to be shaved off to give the L room to get by.

Of course she talks about landmarks such as the Willis Tower, Boeing Headquarters, Marina City, the Merchandise Mart and more. But to my mind, the true charm of the tour is in the less well-known spots. Take the Hotel Allegro, originally the Hotel Bismarck, where from a Pink Line train she points out the figures above two windows: the Pied Piper to lure in travelers, and Saint Christopher to protect them. “I’ve walked down this street many, many times,” she says, “and I never saw those windows until I took this train.”

And then there are the outdoor platforms and bridges. As we stand around gawking at one or another of them, listening to Hensel, Chicagoans hurry past us, seemingly oblivious to views they surely take for granted.

My favorite bridge is at the Madison/Wabash station, which connects all four lines in the Loop. From here, we can see right into the windows of some old Jewelers Row buildings on either side as Hensel tells us about the architects, the materials, the ornamentation. But look right down the tracks, and in the distance, perfectly framed, is the soaring Trump International Hotel and Tower, innovative for being so tall (98 stories) with a relatively small footprint. Why does it seem to fit in so well with surrounding buildings? Each of three setbacks matches the height of a nearby structure. Brilliant.

For another perspective, that afternoon I board the foundation’s popular Chicago River cruise. Docent Barry Aldridge is even more entertaining, peppering the ride with a catchphrase that he thinks best sums up the valuable role of the buildings’ designers: “Kiss your architect.” He points out 35 E. Wacker Dr., originally known as the Jewelers Building, with its distinctive classical dome, and tells us that car elevators were initially installed to provide security for the loaded-down jewelers as they made their way to their offices. For such a great idea, “kiss your architect,” he says. For the Civic Opera Building’s throne-shaped design, intended to maximize the square footage (and therefore the revenue possibilities)? “Kiss your architect.”

As we amble down, up and along the river’s three branches, Aldridge isn’t afraid to play favorites, and that includes 333 W. Wacker, a sleek glass sheath that curves with the turn of the river and echoes its green color. “When a building is being designed, you never know exactly how it’s going to fit in, but this one’s a real blockbuster,” he says.

Like Hensel and her history of the train, Aldridge sprinkles his tour with tales not only of the development of Chicago’s riverfront, but also with the development of the river itself. Perhaps most impressively, the city reversed the flow of water in 1900 to reduce industrial pollution, building a canal that caused gravity to pull clean water from Lake Michigan into the river rather than vice versa. “Some people say that what we flush in Chicago they end up drinking in St. Louis,” he deadpans, “but the river is much cleaner than it used to be.”

When we pass the Willis Tower — Aldridge insists on calling it the Sears Tower, the name that made it famous — he points out that if we look really closely, we can see the outlines of the Ledge, four glass boxes that hold visitors who want to be suspended 103 floors up. That would be yet another interesting perspective on Chicago architecture, no doubt, but just thinking about it gives me vertigo, even from the relative safety of the Chicago’s First Lady cruise boat.

Instead, the next morning I take a walk down to the seven-year-old Millennium Park, where the Frank Gehry-designed Jay Pritzker Pavilion gleams like some sort of giant burnished-metal Christmas bow and children crowd around the Crown Fountain, where towers project images of faces and water sprays turn the whole thing into an exuberant play on the idea of gargoyles.

But I’m most mesmerized by Cloud Gate, a huge shiny bubble nicknamed “The Bean” that reflects, well, everything, with fun-house-like distortion. I’m not the only one enthralled: Groups of children pose for photos on their backs with their feet up on it, doubling the image. Two boys play patty-cake with themselves. And a 30-something guy walks right up to the thing and primps while his girlfriend snaps away with her camera.

I don’t really care what I look like in the thing. I’m more interested in seeing how it bends the image of the skyline, including One and Two Prudential Plaza and the Aon Center, when I look at it from just the right angle. I can’t tear myself away. This was built by artist Anish Kapoor, not an architect, but if he were here I would kiss him anyway.