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.

Seiichiro Nishimoto, CEO of Shelter Co., poses wearing a gas mask at a model room for the company's nuclear shelters in the basement of his house in Osaka, Japan on April 26, 2017. With nearby North Korea increasing its show of power day by day with missile launches and nuclear tests, people in Japan are preparing for the worst by building private nuclear shelters, Reuters reports. (Photo by Kim Kyung-Hoon/Reuters)

A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

Worker Shi Shenwei pulls a wheelbarrow at the construction site of a Buddhist temple in the village of Huangshan, near Quanzhou, Fujian Province, China, September 28, 2016. For most construction workers, lunch is a welcome break to rest and refuel. Not for Shi Shenwei. the 23-year-old spends his midday break jumping and swinging through a maze of scaffolding poles, performing a fitness routine that has made him China's latest social media sensation. (Photo by Thomas Peter/Reuters)

“These are the stunning 360 degree images of Europe's abandoned buildings that will get your head in a spin. Sven Fennema, 33, captured the incredible shots, which include a forgotten villa and casino in northern Italy and abandoned churches in Poland”. – Caters News. (Photo by Sven Fennema/Caters News)

A man looks at a mural painted on the walls of houses in Zaraeeb, created by French-Tunisian artist El Seed, in the shanty area known also as Zabaleen or “Garbage City” on the Mokattam Hills in eastern Cairo, Egypt, April 4, 2016. (Photo by Amr Abdallah Dalsh/Reuters)

A woman poses for her husband alongside a giant camera Thursday, November 7, 2013 outside the Historic Green County Courthouse in Monroe, Wis. Chicago photographer Dennis Manarchy created what's being called the world's largest camera. It's 35-feet long and 12-feet tall it's a working replica of a vintage accordion-style camera that produces 16- by 24-foot prints, the equivalent of a two-story building. The giant camera is on display in Monroe through November 17 because a Monroe company manufactured the specially-built trailer. Manarchy plans to tow the camera around the country to shoot photos of indigenous cultures. (Photo by Mark Hoffman)

Labourers stack dried bricks inside a kiln, where they will be fired, at a brick factory on the outskirt of Sanaa, Yemen, June 1, 2016. Traditional mud brick tower houses have always been a source of pride to Yemenis, and over a year into a devastating civil war, they are also providing some much-needed jobs in the ancient capital Sanaa. (Photo by Mohamed al-Sayaghi/Reuters)