WATERVILLE — Isaac Cooley carved a door in the side of a huge cardboard box that once housed a washing machine, with an eye toward connecting it to a taller refrigerator box out of which he had fashioned a castle.

He crawled inside the tall box, lay down on the floor and peered out the door at his mother, Amanda Cooley.

“I would never sleep in this kind of fun,” said Isaac, 7.

The Cooleys were among dozens of children and adults spending part of their Saturday in the gigantic main hall of the Children’s Discovery Museum of Central Maine, crafting a cardboard city maze from many donated boxes of all shapes and sizes. The museum purchased the former First Congregational United Church of Christ building on Eustis Parkway in November 2020.

The “STEM-a-Palooza” event, hosted by both the museum and the Maine State Library, included the box activity as well as a room in which children programmed robots and played with mobile exhibit activity panels in another space.

Amanda Cooley of Waterville said her son had been looking forward to it all week, since bringing a flyer home from school. It was an unusual activity and one that represents the creative play the museum promotes, she said.

“It’s a nice way to introduce this location,” she said. “It just goes to show if you offer something like this, people will come.”

The museum hasn’t officially opened, but the goal is to do so by the end of this year, according to museum Director Amarinda Keys, who was floating about the 3,000-square-foot hall Saturday, greeting families and helping coordinate activities.

“They’re making robots and airplanes and cars and houses, and the adults are getting involved, too,” Keys said. “They’re getting the moms and dads to play.”

Young people experiment with robots during the “STEM-a-Palooza” event Saturday at the Children’s Discovery Museum of Central Maine in Waterville. Rich Abrahamson/Morning Sentinel

Keys said that while the coronavirus pandemic delayed the museum’s opening, renovations will start soon inside the building to construct new bathrooms and fire egress areas and then exhibits will be fabricated and installed. Meanwhile, the museum has been offering a full slate of programs all year long, she said, including free weekly walks on Tuesdays at Quarry Road Recreation Area. An English tea will be offered May 1, summer camps will be held for four weeks and Touch-A-Truck will be featured at Bangor Savings Bank in June, she said. Events are listed on the museum’s website, childrensdiscoverymuseum.org/programs.

About 75 people turned out for the afternoon event. They included D.J. Adams of Waterville and her children, Izabellah, 5, and Caroline 3, who were programming computers shaped like caterpillars that scooted around on the floor, emitting blinking colored lights.

“I think it’s great for my kids — they just love to learn and explore,” Adams said.

Jordan Moore, who volunteered in the robot room as his wife, Chris, the STEM librarian at the Maine State Library, helped children in the cardboard box city hall. Jordan Moore said children as young as 3 can play with the robots and learn how logic works at the same time.

“This kind of thought pattern — way of thinking — is important as technology continues to evolve,” he said.

The museum’s mission is to ignite curiosity and celebrate learning through play. Formerly located at 171 Capitol St. in Augusta, it has served families for nearly 30 years.