Missed "The Beach" last year? You're in luck. On April 30, Dupont Underground will unveil an all-white installation made with 650,000 translucent plastic balls from the shuttered National Building Museum exhibition. There is one caveat: The concept isn't anything like a ball pit. Instead, the Dupont Circle arts destination will transform about 7,000 square feet of the old trolley station into an interactive building block system that sounds a lot like a life-size Lego world, where visitors can move around blocks and shape the space themselves.

"It's not just about building objects," says Philippa Hughes, a Dupont Underground board member. "It's really dependent on what the person makes of it -- what their intentions are. It's meant to be about community building."

The design -- by New York-based architecture and design studio Hou de Sousa -- won a competition held in partnership between the museum and Dupont Underground that called for entries to reuse the balls from "The Beach." In a statement, the design team likened the installation, called "Raise/Raze," to "a massive sandbox," where people can change their environment easily by constructing or destroying forms. Though shapes will be pre-assembled for opening day, visitors will be allowed to modify them.

To attend the installation, which runs April 30 through June 1, the public will have to reserve in advance; only small groups of about 50 will be allowed in at a time. Admission will cost $15; tickets will be available for purchase closer to the opening date. But if you'd like to make a reservation now, all you have to do is pledge $25 to Dupont Underground's Indiegogo campaign.

"Raise/Raze," Dupont Underground, April 30-June 1.