Emerging from the subway station in Chicago, I walked straight into a dance party.

A phalanx of veteran DJs from the city’s South Side known as the Chosen Few were packing Daley Plaza, and I was reminded that this city birthed a major electronic dance music genre in the 1980s, known as Chicago house. The workday-lunch crowd moved to the beat with palpable nostalgia, in the shadow of a 1967 Picasso sculpture. I had been in the Chicago Loop 5 minutes and I had already found a spontaneous, authentic experience.

When I first knew I’d be in Chicago on a weekday — one long, free weekday with a blank slate — I thought of “Ferris Bueller’s Day Off.” In the movie, Ferris and his hooky-playing pals encounter a parade, which prompts Ferris to perform a choreographed lip-sync to “Twist and Shout.” What is this raucous Chicago movie parade that happens on a school day? Life beyond high school must be amazing!

It turns out the parade in the movie, the Von Steuben German Day Parade, is a real thing. I didn’t find it on a recent Wednesday in Chicago (it returns to Lincoln Avenue on Sept. 10), but the DJ show was a worthy alternative.

It’s easy to walk into something surprising when you’re in Chicago for a day — whether you’re just passing through, or on a cheap day trip by air, minus the steep hotel and parking bills.

But if you’re really watching the clock, you need a plan. Time flies in the Second City, and it’s easy to underestimate the sheer scale of the place. Below are some possible plans of attack. You might want to pick one or two of these and call it a good day.

Navy Pier & Centennial Wheel

The newest attraction on the Chicago waterfront is pretty touristy, but worth a spin. The Centennial Wheel, unveiled in May, is the centerpiece of the Navy Pier’s $115 million, 100th-anniversary makeover. The high-tech Ferris wheel is no London Eye — at 196 feet, it’s actually 68 feet shorter than the original Ferris wheel built for the 1893 Chicago World's Fair — but the air-conditioned gondolas seat eight and easily inspire a little vertigo on the initial ascent. At the top, you sense you’re sitting on the dividing line between two worlds: the wall of modern high-rises on one side of you, and the oddly tropical-hued waters of Lake Michigan on the other ($15; navypier.com).

Stroll the rest of the family-friendly pier. Take a themed sail on the Tall Ship Windy, a four-mast schooner ($30, tallshipwindy.com), or better yet, time your visit for Chicago’s own Tall Ships Festival (July 27-31). Take an “extreme thrill ride” on the lake with 180- and 360-degree spins on the 2,800-horsepower Seadog Extreme cruiser boat ($30, seadogcruises.com).

As for food and drink, the Navy Pier’s revamped options include rum cocktails and regional craft beer. The eateries still lean toward high-end fast food, but the new DMK Burger Bar and Fish Bar boasts a sustainable seafood menu; try the crab sandwich ($15) with well-seasoned Tater Tots.

Bike around

Chicago is enormous — there’s no way to cover a lot of sightseeing ground strictly on foot. But most of the lakefront is highly bikeable.

Divvy is Chicago’s bike-sharing program. Step up to a Divvy kiosk, purchase a 24-hour pass for $9.95 and you’re off. (Pro tip: Register via the app at divvybikes.com/transitapp; I had technical difficulties at my kiosk.) Trips between kiosks, which are everywhere, are free for up to 30 minutes, with modest fees for going longer (divvybikes.com). If you find Divvy’s big blue cruisers a little sluggish, as I did, opt for a hybrid or “fitness” bike for $13-$15 an hour from Bike & Roll in front of the Navy Pier (bikechicago.com).

From Navy Pier, ride north along the water’s edge to the Lincoln Park Zoo, or hit Oak Street Beach, North Avenue Beach or Montrose Beach for an hour of Great Lake swimming and sunning. Or head south through the huge Grant Park/Millennium Park area, home of the Cloud Gate sculpture (aka the “Bean”), the Frank Gehry-designed Jay Pritzker Pavilion concert venue (with nightly performances) and the Buckingham Fountain (from “Married … With Children”).

Further inland, the 606 is an new elevated trail and green space, similar to New York City’s High Line. The 2.7-mile trail links four diverse city neighborhoods, from Wicker Park to Logan Square, with plenty of shops and restaurants along the way (the606.org).

Take a river tour

The standard thing to do is book an architecture cruise through the busy urban trench that is the Chicago River, with cocktail in hand. And it’s worth it for the astounding array of masterful buildings, from the 1924 gem that is the Wrigley Building to the Art Deco details of the Civic Opera House. Tours are offered by Seadog ($39; seadogcruises.com), Chicago Line ($42; chicagoline.com) and others.

I’d already done that before, so I opted for a two-hour history tour via Urban Kayaks ($71; urbankayaks.com). The kayak tour is more adventurous and physically immersive than the cruises, but a little less informative when you’re having fun dodging barges and party yachts. From the low vantage point of the water’s surface, you really get a sense of how the multitiered city was built, and the people-watching is great as workers flood the Riverwalk area for happy hour.

Sights include the broad 1930 Merchandise Mart (once the largest building in the world), and a 98-story modern structure that is now the city’s second-tallest building, emblazoned with the name of a certain presidential candidate.

Among the tidbits I learned from Jim, our guide: The Chicago River was actually engineered to flow backward from Lake Michigan; and the city’s two-tier construction, with the lower level once ruled by Al Capone, is what gave us the term “underworld.”

Drop by the neighborhood

The sun was getting low, but no visit to this city is complete without experiencing actual Chicago neighborhoods. I chose the famed rock ’n’ roll haven of Wicker Park, partly because it was on the train line back to O’Hare Airport. The increasingly gentrified Wicker Park is still one of the more walkable districts in the city.

I ducked into Emporium Arcade Bar on Milwaukee Avenue, an easygoing two-room saloon with 47 arcade games (mostly from the ’80s), 11 pinball machines and 28 beers on tap. A horror movie was being projected onto a 20-foot screen. It took me a dollar’s worth of tokens to remember how to master Paperboy, the bicycle-controlled game that first got me into journalism (emporiumchicago.com).

From there, I wanted to hit a hot Wicker Park burlesque bar called Bordel, but unfortunately I had a 10:05 p.m. flight home to catch at O’Hare. I reluctantly forced myself back to the train station, leaving a few items on my to-do list.

Seeing enough of Chicago in only one day is a fool’s errand, but that doesn’t mean you can’t have fun trying.