When 11-year-old Sergio Paul walked into York Academy Regional Charter School for York's first Cardboard Challenge Saturday morning, he saw endless opportunities.
At least three pickup truck-loads of cardboard were piled on the gym floor, and a variety of art supplies were scattered across a set of bleachers.
In the center of the gym, groups of children were hard at work building everything from houses to robots to racetracks.
"I saw all these wonderful inventions," Paul, of York City, said, his eyes lighting up. "I thought, 'Hey, what (can I make) that people like?'"
Right away, Paul knew he wanted to make something that others could enjoy, he said. Just like Caine Monroy, the 9-year-old boy who inspired the Cardboard Challenge.
The Imagination Foundation started the challenge four years ago after the release of the short documentary film "Caine's Arcade," Kelley Gibson, York Cardboard Challenge organizer and Cultural Alliance director of communications, said. The film told the story of how Monroy built an entire arcade out of cardboard boxes for his family and friends to enjoy.
Last year, 125,000 people from 46 countries participated in the annual event, where groups of all ages are encouraged to build anything they can dream up using cardboard, recycled materials and their imagination.
This year, for the first time, York participated in the challenge, organized by the Cultural Alliance of York County and a group of York volunteers.
"I just thought if they're doing this all over the world, I wanted to (organize) it so we had a way to participate," Gibson said.
The event drew about 12 families and groups, including close to 40 children, she said.
Paul, who decided on building a cardboard skee ball machine that he could enjoy with his friends, said he wouldn't have missed the challenge. He even skipped his karate class to attend.
"It was a once-in-a-lifetime chance," Paul said, adding that he'd never participated in a world-wide event before.
Like Paul, several others created various games on Saturday.
Inspired by "Caine's Arcade," Strand-Capitol Performing Arts Center CEO Todd Fogdall and his son Cade built games similar to skee ball and pinball.
But most of Saturday's creations varied from trains to trucks to castles and other structures.
"We love doing this kind of thing at home," Jennifer Tansey, of Spring Garden Township, said. She and her two children built a cardboard house with another family they met at the challenge.
"It was truly community collaborative arts," she said.
Several of the larger pieces — including the Tansey's house, a robot and a pizza food truck — will be on display in the Martin Library atrium starting Monday.
For those who want to try the Cardboard Challenge at home, here are a few tips from Saturday's participants.
1. Make a plan.
Sometimes it's fun to be spontaneous, but Gibson said it's best to know what you plan to build in advance so you can gather the appropriate supplies. Try to choose something like a doll house or a game that your children will want to play with again and again, she said.
2. Use all of the art supplies you can find.
Don't limit yourself, Gibson said.
"When we put all of the supplies out, we didn't know if people were going to figure out how to use half of it, but the strangest stuff got used," she said.
Some of the supplies Saturday included buttons, crochet boards, googly eyes, straws and nail polish. Colored tape and a box cutter or really good scissors are a must, she said.
3. Draw inspiration from the size and patterns of the boxes.
That's how Tansey and her two children came up with the design for their house. They used colorful granola bar boxes and Cheez-It boxes for the roof shingles, a blue patterned box for the window shutters and yellow boxes for lights next to the front door.
4. Let the children be the directors.
The Cardboard Challenge is an opportunity for children to use their creativity, Tansey said, but make sure a parent is there to help when it comes to using sharp tools.
5. Do the challenge with a group of people.
The more minds you have, the better because everyone comes from a different perspective, Laura O'Grady, coach of Martin Library's Robotics Team, said. O'Grady and a group of six students, grades four through eight, collaborated to build a robot Saturday.