Getting your Trinity Audio player ready...

In a city like Chicago, with its incomparable architectural heritage, it’s unusual to pay much attention to the opening of a parking garage.

But the extraordinary nature of the one opening at the Museum of Science and Industry Monday–and the larger implications it has for one of the most venerable cultural institutions in the city–makes it more than a place to leave your car for a few hours.

In fact, the garage is an addition to the museum itself, given that patrons will be able to park and enter a cavernous, soaring entryway rising four stories high, graced with exhibits, gift shop and cafe as well as the admission booths.

“Certainly, there’s no other cultural institution in the city where you can park your car indoors, walk indoors to the entrance and never venture outside during your entire visit,” says David Mosena, the museum’s new president.

He is clearly proud of the museum’s new garage and “Great Hall” entryway and just as relieved to see the end of the grindingly long and messy construction process.

An eyesore of excavations and mud for two years, the new three-story garage now is entirely underground and soon will have a lawn growing on top of it.

During those long months, attendance fell off and irritation in the neighborhood grew.

Museum officials hope that at a time when the Field Museum, Adler Planetarium and Shedd Aquarium are getting all the limelight for the opening of their combined “Museum Campus,” the new addition will give the Hyde Park institution some added cachet as well as more robust attendance.

The grand opening of the garage, with ribbon-cutting and speeches, will take place July 16. But the garage will be open for business Monday.

“We want to make sure all the kinks are worked out of the new facility and the new ticketing stations . . . before the official grand opening,” Mosena says.

That means, beginning Monday, visitors will get a sneak preview of the $48 million structure, as well as a passenger train on display that happens to be one of the most glamorous in the history of railroading.

The Pioneer Zephyr, the world’s first diesel electric train, is a beautiful, streamlined stainless-steel legend that broke speed records and inspired industrial designers in the 1930s to streamline everything from toasters to vacuum cleaners.

Completely restored after spending 34 years deteriorating outside the museum, the historic 64-year-old train gleams in an atrium running through the center of the 1,500-space garage.

One of the largest and classiest historic artifacts to be seen anywhere, it will be the first thing visitors see.

Guided tours of the Zephyr are expected to be offered a week or so before the garage’s formal opening.

The new Great Hall entrance from the parking garage into the 64-year-old museum must rank as one of the most glamorous of any cultural institution in the world.

As big as an airline or railroad terminal, the Great Hall eventually will be appointed with the museum’s main store, a coffee shop, visitor planning center and a number of displays.

Already hanging in the Great Hall is one of the museum’s newest acquisitions: NASA’s exact replica of the Cassini space probe, a six-ton space vehicle now on its way to a 2004 rendezvous with Saturn.

Mosena says the museum is hoping that the 30,000-square-foot addition will perk up attendance, which has been flagging much of this decade.

The worst drop came in 1991, when the museum instituted an admission fee.

The number of visitors fell to 2,176,000 from 3,785,000 the year before. Attendance leveled off at 2 million a year in 1995, but with construction of the garage beginning in 1996, the number of visitors has continued to plummet, to 1,680,000 last year.

“With the construction finished, we think that should change,” says Mosena.

“I expect the garage to become a great new asset for the institution.”

Part of that expectation is based on the beautifying aspects of the project, which, by putting the garage underground, restores six acres of green space to the museum grounds.

Previously, the main parking lot sprawled in front of the museum. That area, the roof of the new garage, will become a lawn.

“As Jack Kahn, my predecessor as president here, says, the garage makes us a museum in a park, instead of a museum in a parking lot.”

The garage, which costs $5 for all-day parking, has 500 more parking spaces than the old parking lot, which was free.

Mosena, who took over the museum when Hahn retired last fall, is pushing to mix new, state-of-the-art exhibits with standby artifacts.

“Kids like the new exhibits, but half of our visitors are adults, and they like to come here for the nostalgia of the old stuff.

“This institution’s strength is its huge icons, the coal mine, the submarine, the Zephyr and our old steam engines,” Mosena says.

“There is no other place in this country that has these kind of artifacts. It’s important to preserve them because that is what makes us unique.”