Dancers take part in a parade to mark the opening of the annual Bali Art Festival on a main road in Denpasar, Bali, Indonesia, 12 June 2022. The Bali Art Festival runs from 12 June to 10 July 2022 and features hundreds of performers. (Photo by Made Nagi/EPA/EFE)

This photo taken on November 20, 2022 shows a woman wearing the Chinese transitional dress, known as Hanfu, taking part in a parade in Shenyang in China's northeastern Liaoning province. (Photo by AFP Photo/China Stringer Network)

Balinese dancers perform as they take part in a cultural parade, during a new year's eve celebration at a main road in Denpasar, Bali, Indonesia, 31 December 2022. (Photo by Made Nagi/EPA/EFE/Rex Features/Shutterstock)

Actress Anne Hathaway attends the “The Dark Knight Rises” World Premiere at AMC Lincoln Square Theater on July 16, 2012 in New York City. (Photo by Jim Spellman)

Actress Emma Watson attends the World Premiere of Harry Potter and The Deathly Hallows – Part 2 at Trafalgar Square on July 7, 2011 in London, England. (Photo by Ian Gavan/Getty Images)

Rowan Atkinson attends the UK premiere of Johnny English Reborn at The Empire Leicester Square on October 2, 2011 in London, United Kingdom. (Photo by Dave Hogan/Getty Images)

Last weekend, the National Building Museum in Washington, D.C., opened a 10,000 square-foot ball pit to the general public, and everyone cheered that, finally, someone made their childhood dreams come true.

The 150-square-metre Villa Ypsilon was designed by London- and Brussels-based firm LASSA, which is headed up by architects Theo Sarantoglou Lalis and Dora Sweijd.