Growing up, we had a simple architectural dream: to live in a loft apartment with bunk beds, a pinball machine, and a enormous trampoline — just like Tom Hanks’ manchild character in Big. Now that we’re older, we find that our tastes haven’t changed much; we’re still in the market for a livable fun house that fulfills the over-the-top wishes of our inner child. After the jump, we’ve rounded up some architectural structures guaranteed to delight the kid in you. Leave a comment if you know of a cool building that we’ve left out.

Japanese architect Terunobu Fujimori‘s surreal Tree House is certainly an upgrade from the wooden planks that rested on the rickety branches in our backyard. Situated in Nagano, the structure is elevated 20 feet and sits atop two tree trunks. As he explains it: “One leg is dangerous and three legs are too stable and boring.”

You remember the flimsiness of LEGOs. With just the flick of the wrist, a carefully-crafted design could be shattered in an instant. Unfortunately, this holds true even when a whopping 3.3 million little bricks are involved. That’s what happened when James May of the BBC show Toy Stories built and designed a two story house made of the boldly-colored pieces. The entire process took two weeks, but a lack of prospective buyers resulted in the demolition of LEGO Land.

British architect Laurie Chetwood seems tuned into a child’s interest in insects and animals. Her 2003 Butterfly House in Surrey, England, is described as a zoomorphic design; that is, the design is highly-stylized with animal motifs. But the house is not without a look into the life cycle. Theme-based rooms range from the larval stage to chrysalis, and finally, the materialized butterfly — wings and all.

Madrid’s CaixaForum Museum is virtually a vertical jungle, although it may be a bit more sophisticated than the jungles of our childhood imaginations. Architects Jacques Herzog and Pierre de Meuron (the men behind London’s Tate Modern museum) collaborated with famed botanist Patrick Blancon on the outdoor facade aligned with 15,000 plants from 250 different species.

The guys behind MUT Architecture (who just produced this bar in Paris that we’re dying to try) came up with this mock water slide within Frank Lloyd Wright’s circling atrium at the Guggenheim. We can’t imagine anything more fun than the splashing around with Kandinsky’s Compositions flashing by.

French designer Jean-Marie Massaud‘s Manned Cloud is a whale-shaped floating hotel designed to accommodate 40 guests and travel at speeds of up to 100 miles per hour(!). There’s also a restaurant, spa, and a fitness center — cruise ship-style amenities that appeal to the adult in us, too.

Would you want to live in any of these playful structures?