If I could gather everyone I know, and share one place with them, it would be the City Museum, St Louis, MO. I would take you there because it's a model for how art, play, learning, and challenge can convene in a single place. This place shows how the comforts and conveniences of our structures and systems have ruined our fitness and creativity. There are interactive exhibits of 50s nostalgia, a big ol' bug collection, a massive cave network, a tree climbing/crawling network, huge multi-story slides, urban archeology zones, epic contemporary sculptures, rooms that are self-playing instruments, human hamster tunnels and so much more. There is a circus school INSIDE where the kids get the chance to perform several times a day. At City Museum, the artists have run wild with what seems like little concern for 'safety' (I'm not talking about legitimate dangers, but the type of fear that conditions parents, leaders, and law enforcement to tell us not to climb, explore, and challenge convention). In no other museum have I laughed, sweated, cried, and used every possible primal pattern just to get around.
I want airports with open spaces and monkey bars, floor seating options in all restaurants and places like the city museum all over the world.