A park that can be enjoyed in even the most frigid of winters, hidden beneath the streets of Manhattan and fueled with solar technology -- must be science fiction, right?

Wrong. The Lowline, housed in an abandoned trolley depot on the Lower East Side, is set to become a reality in the next five years -- and over the next two weekends, New Yorkers can head to the Mark Miller Gallery for a sneak preview of the not-too-distant future.

From 1-2 p.m. on Saturday and Sunday, the Lowline co-founders will host what they've deemed "Tech Play Day," an exhibition of the project's fiber-optic technology.

The science behind the Lowline "seems like a very complicated set of scientific principles, but it's actually very simple," said Dan Barasch, a co-founder.

"We'll have some interactive exhibits that [co-founder] James [Ramsey] will use to demonstrate the technology," he said, as well as "small workshops for kids and whoever wants to come learn about the science of directing light."

Visitors will also be encouraged to share their own ideas for the project, he added.

In addition to hosting Tech Play Day, the gallery is currently exhibiting the results of the Young Designers Program, a collaboration between the Lowline creators and Lower East Side middle schoolers. Over the past few months, the Lowline has teamed up with local neighborhood groups to help kids envision the future of their community. Around 30 have participated so far, Barasch said, touring other city landmarks like the High Line and then creating models of their suggestions for the Lowline.

Overall the young designers' ideas have spanned a wide variety: some proposed "really practical things, like having retail and food," Barasch said, "but there's also some really fanciful and crazy stuff. One of my favorites involves underwater elements with mermaids."

"That's what's fun about working with kids this age," he said. "They're more than capable of crafting pretty complex ideas, but they also have a ton of creativity."

The Young Designers exhibit will run through Sunday, March 9.