Imagine you are 8 years old, riding a yellow school bus on a third-grade field trip.

Nose pressed to the window, you pull up to a festive structure with colorful sailcloth canopies marking the way to a large, glass-fronted entry hall.

You're tempted to climb on the play equipment on a well-landscaped lawn with a stream running through it, or tumble down a nearby hill.

But your teacher keeps the class corralled, saying there will be time for that later.

Once inside, you gather for orientation in a theater/reception area and then begin making your way through soaring spaces packed with exhibitions on nature, science and art, from a Spy Academy to Little Town to a giant kaleidoscope to a wind tunnel and an interactive projection stage and sound-sampling studio. You dabble in robotics in the Think-U-Bator, piece together a giant map of the United States in Explore My World. Outside, you gather for storytelling under a 100-foot live oak. Now it's time to tackle that tumbling hill. ...

Welcome to the San Antonio Children's Museum, the 2.0 version, a $46-million, 68,000-square-foot compound being constructed on a 5.4-acre site on Broadway at Humphrey Street. Fundraising is 90 percent complete, said museum director Vanessa Lacoss Hurd, with the largest gift of $20 million coming from Charles Butt, chairman and CEO of H-E-B, in 2011. The City of San Antonio contributed $3 million.

“San Antonio children are tops and they deserve a first-class children's museum,” Butt said in a statement at the time. “When properly done, children's museums contribute significantly to the creative development and education of our young people.”

Set to be finished in a year, the children's museum will open to the public in June 2015 after its 27,000 square feet of indoor gallery space and 19,000 square feet of outdoor space are outfitted with hands-on exhibitions.

“Each of the exhibit halls will be like a toy chest,” said Greg Papay, a partner at Lake | Flato Architects, which is designing the museum, along with Argyle Design, a New York firm that specializes in children's museum exhibitions, and Ten Eyck Landscape Architects of Austin, which is in charge of transforming a heavily asphalted former car dealership into a midtown greenspace. “You open it up and all this crazy stuff is going on inside.”

But it's not all fun and games, Hurd said.

She and her staff spent several months “around a table” with designers, educators, parents and community leaders formulating exhibitions that kids will love — and learn from.

Children up to age 10 — the museum's target audience — will be able to explore processes, systems and materials through “deeply interactive” exhibitions with a focus on math and science.

“We're really interested in teaching kids how to think, not what to think,” she said. “So there will be an emphasis on problem-solving.”

In the Spy Academy, for example, children will build their own profile — name, persona — and use that profile to complete a series of challenges throughout the lab. They may get a chance to have their name entered on the Spy Wall of Fame.

In addition to nearly doubling the museum's physical space, Hurd expects attendance to increase from 170,000 annually at the current downtown location to more than 300,000 at the Broadway site.

“And the vast majority of that increase will be our own residents,” she said, adding that a pillar of Mayor Julián Castro's sa2020 initiative is early childhood development — and the children's museum's mission dovetails with that.

“We want to teach kids to be 21st-century thinkers,” Hurd said.

The children's museum opened at its current East Houston Street location in 1995. Parking and an absence of outdoor attractions have long been problems, and the new campus goes a long way toward solving them. It will have about 250 parking spaces for visitors and staff, as well as a verdant surrounding landscape, with a “front yard” along Broadway devoted to “active play,” Hurd said, and “a back yard” that is more “contemplative,” with a 70-foot stream crossed by wooden bridges.

Unlike art museums, which often make grand architectural statements, children's museums are more about what's going on inside.

“The exhibitions often trump the architecture,” Hurd said.

Yet Lake | Flato project manager Trey Rabke has created a striking architectural addition to the burgeoning Broadway corridor, which continues to undergo revitalization from the Museum Reach section of the River Walk to the development around Pearl Brewery to the ongoing renovation of the Witte Museum.

“We love the opportunity to be a part of that cultural corridor for the city,” Hurd said.

Another problem with the current museum is its verticality, Hurd said. Children's museums should be horizontal spaces, she said, and the new museum will allow kids to “connect the dots across subject matter” through a series of three exhibition halls connected by light-filled glass transitional spaces. Visitors can see what's going on outside, and Broadway commuters can glimpse what's happening inside.

The two-story boxlike structures, staggered in a north/south stairstep configuration along the site, will feature tinted concrete walls — one in yellow, another in red and the third in green — connected to the foundation in what is known as a tilt-wall construction method. The walls will be formed on site and literally tilted up on the ground floor by construction crane. It's a less expensive method of construction used by big-box stores such as Walmart and Home Depot, but, as Rabke quickly pointed out, “much more imaginative.”

“We've designed the buildings with the exhibitions in mind,” he said.

“Overall, the buildings could be an exhibition about architecture,” Papay added.

Hurd said the goal of the children's museum is to not only be a fun place for learning opportunities for kids, but to be an educational resource for their parents and teachers.

“We want to go from a nice-to-have in the community to a must-have in the community,” she said.

sbennett@express-news.net