For Bronx Children’s Museum, a Long-Awaited Home

It’s not just a big purple school bus anymore.

The Bronx Children’s Museum, which operated without a building for more than 10 years, long mounted its exhibits inside a mobile — and unmissable — flamboyantly painted bus. The vehicle may not have traversed time and space, like the one in Joanna Cole’s “Magic School Bus” books, but it offered its own enchantment: a children’s museum in the only New York City borough that had never had one.

Now, however, the museum has walls as well as wheels. On Saturday, it will open a permanent home on the second floor of a former powerhouse, built in 1925, in Mill Pond Park in the South Bronx. Designed by O’Neill McVoy Architects, the 13,650-square-foot museum interior gently winds, evoking the Harlem River just outside.

“One of the big overarching themes for us has been water connects us all,” Carla Precht, the museum’s founding executive director, said in an interview at the building. The riverfront location means the museum’s programs can easily draw on the natural world.

So do its displays. The project, which cost about $17 million (excluding exhibits and artwork), invites children to construct modular bridges and boats for a 35-foot-long model waterway, build and frolic inside a mock beaver dam and investigate local flora and fauna.

They can celebrate the borough’s urban side, too, by exploring the booming culture of an imaginary Bronx block, creating work alongside professional artists and eventually recording songs in a studio. One of the spaces that is still being finished, a multimedia room called the Cloud, will regularly offer “Bronxtopia,” an interactive installation by the Bronx artist Jerome LaMaar that lets children boogie with funky digital avatars.

“I always say that we built this museum from the outside in,” Hope Harley, who was its first board president, said. “Other museums build the big brick-and-mortar and open up, and then they do outreach programs.” But, she added, “We said, ‘No, we can’t wait.’”

Or rather, they had waited long enough. Conceived in 2005, the museum spent years raising funds and seeking a suitable home. Even after finding the riverside site in 2009, it faced bureaucratic hurdles and competition from other prospective tenants. So, in 2011, the donated purple bus became a “launching pad,” Harley said, to deliver its programs to a borough where more than a third of children live in poverty. (To maximize accessibility, the museum, which requires online reservations, will initially be free; the eventual charge will be $8 for visitors over 1.)

A stable group of longtime supporters has helped the museum persevere, including two high-profile women whom Precht called its “godmothers”: Associate Justice Sonia Sotomayor of the United States Supreme Court and Sonia Manzano, the Emmy-winning writer and actress who created the PBS children’s series “Alma’s Way” and played Maria on “Sesame Street.”

Proceeds from sales of “The Lowdown on the High Bridge,” Manzano’s 2014 picture book about the former aqueduct linking the Bronx and Manhattan, go to the museum, which asked her to write it. And Manzano and Sotomayor have regularly appeared at celebrations for the museum’s Dream Big summer arts enrichment initiative.

The building honors both women with Sonia’s Corner, a rotating exhibition space and resource room that currently features their life stories and work. (The justice writes picture books, too.)

“I remember being a kid in the Bronx and not having aspirational places to go to, or a place that we could call our own,” said Manzano, who will visit the museum on Saturday to read her High Bridge book. This building will be just that. “The kids will see things in their own neighborhood exalted,” she said.

While some children’s museums are easy to imagine in any site, this one is deeply rooted in its location. The space, with borough maps and signage in English and Spanish, was designed both for and by Bronx children, who were asked what they wanted to see.

“The first thing they said was dinosaurs,” Precht recalled. “The second thing was animals.”

The museum could fulfill at least one of those requests. Its exhibit “The Woods” includes a three-toed box turtle, a western hognose snake and marine life native to Long Island Sound. Although they are the museum’s only live animals, creatures appear elsewhere as puppets, costumes, microscope specimens and “Bronxtopia” avatars.

Even “The Nest,” a carpeted area of low-to-the-ground interactives for infants and toddlers, has small, peek-in dioramas featuring cuddly raccoons. Natalie Collette Wood, an artist and the museum’s deputy director of arts and exhibits, designed them for this space, which she called “a baby obstacle course.”

At the museum, “we’ll be talking about how nature was the first architect, the first artist, really, and also how that connects to all the artwork,” Wood said.

Relating the art installations to the exhibits’ content was one of the museum’s priorities. Most of the museum’s 10 site-specific installations — its Arts Builds Community collection — were inspired by work that children created in outreach programs.

“There were a lot of images that look like the molecular structure of water in the drawings the kids were doing,” the artist Saya Woolfalk said. “A lot of the kids were also really interested in fantasy and color.” Those elements are incorporated in Woolfalk’s “Mandala to Water,” a massive sculpture of glass and painted steel in the museum’s lobby, and her accompanying digitally printed mural.

C.G. Esperanza, a children’s book author and illustrator who designed the block inside the museum — complete with bodega and veterinary clinic — also drew on children’s work to imagine its casita, a festive neighborhood gathering place filled with Bronx iconography. Over the next year, he will host workshops and show art in the museum’s loft, which is also going to be outfitted as a studio.

“I just really want kids to recognize how much the Bronx has contributed to culture around the world,” Esperanza said.

Although children did not offer input on the museum’s constantly curving architecture, they have influenced its layout.

“We actually designed the space from a kid’s-eye perspective,” the architect Chris McVoy said. The floor inclines so that the “Waterways” exhibit is at the same level as the building’s windows, enabling children to watch the river. A suspended walkway traverses the entire space, with peepholes at a child’s height punctuating its low, translucent walls.

“There are no dead ends,” McVoy said in a walk through the interior. “Everything is about flow and movement.”

But even with a permanent base, which will at first be open to the public only on Saturdays (Tuesdays and Thursdays will be added in January), the museum will not simply stay home.

“We can’t just be a building,” said Precht, who plans to step down now that the project has come to fruition. “To really be an enrichment resource for children, we have to be out in their neighborhoods.”

That means that more programs — and, eventually, a new museum school bus, this one electric — are destined to hit the road.