as the queen city of architecture in the United States, Chicago takes its buildings and its urban fabric seriously.

The morning after a million or so people crushed into Barack Obama's victory rally in downtown Chicago, the city's streets were spotless. Or so I was told by a neophyte Chicagoan who had moved there from Minnesota two years ago and was dazzled by the post-election cleanup.

I could believe it. The Chicago I encountered on a recent visit was so spotless it reminded me of Paris in 1989 when, during the run-up to France's bicentennial, the capital's streets were flushed and scrubbed each morning and even the trash bins in the Metro got polished.

Lots of things about Chicago reminded me of Paris this spring, especially the city's enthusiasm for greenery. Masses of glorious tulips bobbed in beds outside Michigan Avenue shops, pansies spilled from enormous planters near Millennium Park and a small army of gardeners transplanted perennials around the Shedd Aquarium and the Field Museum.

Perhaps Chicago is just polishing its image as part of its bid to host the 2016 Olympics, as some cynics suggest, but my guess -- and hope -- is that my former home has simply embraced its motto "Urbs in Hortus: City in a Garden."

Certainly it is a city transformed from the 1970s, when I lived in Hyde Park, the South Side area now identified as Obama's neighborhood. That part of town was tough and shabby back then. Break-ins were common, and everyone wore whistles on neck chains to summon help.

Chicago today is astonishing, a glamorous and wealthy burg that flaunts its world-class cultural aspirations. Following are highly recommended excursions and downtown highlights

CHICAGO ARCHITECTURE FOUNDATION

224 S. Michigan Av.

1-312-922-3432

www.architecture.org

CAF stages architecture exhibitions and offers more than 85 bus, boat and walking tours of city neighborhoods and landmarks. Special events and tours this summer celebrate the centennial of architect Daniel Burnham's influential 1909 Plan of Chicago, which is still shaping the city's evolution, and the reopening of Mies van der Rohe's ex-urban Farnsworth House, now being restored after flooding in 2008. Specialty tours focus on everything from Tiffany glass to bungalows, cemeteries, Millennium Park, Frank Lloyd Wright buildings and sites associated with influential women.

The "Highlights by Bus: Glessner House" tour ($40) I took included the financial district (Board of Trade, Rookery, a Philip Johnson tower) and Hyde Park, site of Daniel Burnham's 1892-93 World's Columbian Exposition or "White City," which celebrated neoclassical design and boasted the world's first Ferris wheel. We glimpsed the Secret Service barricades around the Obama house before heading to Mies van der Rohe's modernist masterpiece, Crown Hall, on the campus of the Illinois Institute of Technology, and Glessner House, a 1887 rusticated granite manse by H.H. Richardson whose preservation launched the CAF in 1966. North Side highlights included drive-bys of noteworthy Gold Coast mansions, hotels and schools.

The foundation's 90-minute boat tours pointing out skyscrapers lining the Chicago River are fabulous. Thursday's 5:30 p.m. cocktail cruise ($32) is a perfect date-night outing that matches fountains of information with breezy views of such iconic buildings as Trump Tower, the Wrigley Building and Marina City. Reservations strongly recommended.

For tickets: 1-800-982-2787 or www.architecture.org/tours or www.ticketmaster.com/rivercruise.

CHICAGO CULTURAL CENTER

78 E. Washington St. (at Michigan Av.)

www.chicagoculturalcenter.org

1-312-744-6630

Housed in the city's splendid former library across the street from Millennium Park, the Cultural Center is an underappreciated gem. Concerts, dance performances and exhibitions are regularly staged there, but the 1897 building's white marble interior is the high point. Its halls and stairways are lavishly decorated with green and gold mosaics, mother-of-pearl, semiprecious stones and gleaming bronze grilles and light fixtures. Crowning it all is the world's largest Tiffany glass dome, a peacock-hued fantasy 38 feet in diameter set with 2,848 bits of opalescent glass. A second, more somber, rose-and-gold dome tops a pink marble hall memorializing Illinois veterans of the Civil War. The Chicago Office of Tourism runs an information center in the lobby.

ART INSTITUTE OF CHICAGO

111 S. Michigan Av.

1-312-443-3600

www.artinstituteofchicago.org

Renowned for its extensive collection of Impressionist paintings, the AIC's new $300 million Modern Wing by Renzo Piano makes it the country's second-largest art museum, after the Metropolitan in New York. With three floors of new galleries for 20th-century European painting and sculpture, contemporary art, architecture and design -- plus new restaurants, shops and a 600-foot bridge linking it to Millennium Park -- the museum is a world-class treasure house of culture.

MILLENNIUM PARK

Michigan Avenue at Monroe

www.millenniumpark.org

The 24.5-acre park became an instant landmark when it opened in 2004, a civic magnet that lures 3 million people annually to free concerts in a fanciful open-air pavilion designed by Frank Gehry, free ice skating (November through March), and imaginative sculptures including a gigantic mirrored "bean" by Anish Kapor and a fountain in which faces of 1,000 Chicagoans appear behind the water. Through Oct. 31 the park is home to two temporary pavilions, designed by architects Zaha Hadid and Ben van Berkel, that are part of a citywide celebration honoring architect Daniel Burnham (see below).

HAROLD WASHINGTON LIBRARY CENTER

400 S. State St.

1-312-747-4875

www.chicagopublidlibrary.org

Named in honor of the city's first black mayor, the flamboyant post-modern building was designed in 1991 by Thomas H. Beeby, who had an affinity for gargoyles. Enormous green owls and other winged creatures glower from cornices atop the rust-colored brick-and-granite building, which gives steroidal expression to such characteristic tropes of Chicago architecture as recessed ribbons of glass, Palladian windows, Sullivanesque arches and thick masonry walls. On the ninth floor is a beautiful, two-story winter garden near the special collections exhibits, which includes a very moving account of the mayor's life. Don't miss the elegant mosaic mural "Events in the Life of Harold Washington" by Jacob Lawrence in the first-floor lobby.

SHEDD AQUARIUM

1200 S. Lake Shore Drive

1-312-939-2438

www.sheddaquarium.org

An aquatic research institute as well as a popular attraction, the Shedd has a fabulous array of fish displays from the world's major water systems, including the rivers of Asia and India (Mekong, Ganges, Yangtze), the Great Lakes and a Caribbean reef. The sea horse and sea dragon tanks are sure winners, and the Amazon display is mesmerizing with a 5-foot-long catfish drifting past and at least 20 kinds of piranhas. In May the Shedd finished a nine-month refurbishment of its Oceanarium, which includes a "polar play zone" where kids ages 2 to 7 can observe beluga whales and dress up as penguins, among other things.

FIELD MUSEUM OF NATURAL HISTORY

1400 S. Lake Shore Drive

1-312-922-9410

www.fieldmuseum.org

The Shedd Aquarium, the Field Museum and Adler Planetarium are part of what the city has now dubbed its "museum campus." With its collections of gems, bones and ethnic artifacts, the venerable Field Museum seems a little musty when compared with the bustling aquarium across the park, but the museum is trying to boost its popularity, too. This summer's banner attraction is "Real Pirates: The Untold Story of the Whydah, From Slave Ship to Pirate Ship." It's a complicated story, well documented, thoroughly researched and dramatically told with costumed mannequins, musical flourishes and lots of maps, charts and narrative panels about slavery and pirate life (through Oct. 25).

A DANIEL BURNHAM CELEBRATION

Architect Daniel Burnham (1846-1912) believed that urban amenities such as parks, libraries and public transportation were civilizing influences that strengthened the moral fiber of the populace. He brought international attention to Chicago with the World's Columbian Exposition of 1893, which celebrated the 400th anniversary of European "discovery" of the New World. Critics sniped that the fair's nouveau Greco-Roman architecture set modern design back for decades, but the event was a triumph for the city and sealed Burnham's reputation.

His 1909 Plan of Chicago is equally legendary, a program of radiating boulevards and grand buildings intended to make Chicago into a cultural, commercial and transportation hub.

To mark the centennial of his Chicago Plan, the city is honoring Burnham with exhibitions, tours and publications. Tours include lobby of the Rookery (209 S. La Salle St.), which was designed by Burnham and his business partner John Wellborn Root and later remodeled by Frank Lloyd Wright.

Diagonally across the street at 190 S. La Salle St. is an elegant post-modern tower by Philip Johnson and John Burgee. In the lush, gold-leaf-and-marble lobby hangs a beautiful 18-foot tapestry by Swedish artist Helena Hernmarck re-creating, in wool and linen, Burnham's most famous design from the 1909 city plan.

For more about Burnham exhibitions, tours and events, see www.burnham plan100.org.