And that’s exactly what they do on Maryland Day, the annual open house when they throw open the College Park campus’ doors to the community.

All 13 schools and colleges get together to squeeze more than 400 activities into six hours of tours, exhibits, demonstrations, and sporting events. There are live choral performances on the lawn, dance lessons in the performing-arts center, Chinese-language lessons, health screenings…and it’s all free. Even the parking.

Of course, there’s also the typical festival fare of face painting, moon bounces, and crab cakes. It would be sacrilege without them. But the school has its sights set a bit higher when planning this last big blowout of the year: They’re looking to exact some serious influence by interacting with their surrounding communities—especially the kids.

“Universities these days are connecting with the communities, and that’s not just the national laboratories and corporations, but high-school and grammar-school kids and various organizations that are not just local, but at the state and national levels—the world, as a matter of fact,” says Dr. Dan Mote Jr., Maryland’s president, who, 12 years ago, brought the template for this massive show-and-tell across the country from his previous post at Berkeley.

Mote’s ultimate goal is to reach young kids to give them a glimpse of the excitement that goes on at Maryland and get them amped up about education.

“We try our best to get schools to bring in busloads of kids, to get families to bring neighbors and friends, and grandparents to bring their grandkids,” Mote says.

“The U.S. has a decreasing population of people going to university. Most people don’t realize that, and this is a very, very troubling prospect for the future for our country.”

Whether or not the general population is aware of a national educational crisis, the people come en masse (70,000 visitors showed up last year, including 400 who flew over from India). Alumni reconnect with their college days, prospective students talk to undergrads and professors to see what college is like, families break free of the house because it’s finally spring, and urbanites escape the city for the relief of trees and grass.

“We’ve been back two or three years. We do ice cream, animals, the moon bounce,” says Julio Duarte, who, with wife and fellow alumni Celeste and their 4-year-old daughter, drove from Virginia for the festivities.

He stands in the serpentine line for a scoop of Maryland’s homemade and seriously delicious ice cream from the Dairy. The family also attended the Alumni Reception for the unveiling of the life-member wall. And then it was on to the Student Union.

“They have a bunch of games—a bean-bag toss, and you can kick a big soccer ball over a net to win a prize,” Celeste says.

And it really is education masked as playtime as far as the eye can see. Future archeologists go digging for fossils on a sandbox hunt, and prospective virtuosos try their musical skills on trumpets, flutes, and cellos at the instrument petting zoo. There are dance lessons (hip-hop to salsa), fire-safety demonstrations with controlled flames, a robot racetrack, peat-pellet gardening, and even a magma-maker demonstration.

The 2010 event will have an environmental bent in honor of the 40th anniversary of Earth Day. Stop by the Office of Sustainability Tent on McKeldin Mall, which becomes Terp Town Center for the day, for ideas on making your home and lifestyle more sustainable. Talk to Earth system scientists from NASA on Science & Tech Way; they’ll help you build your own instruments to measure winds and rainfall.