Hydrofloors: A Vertically Retractable Swimming Pool (Finally!)

I don't know what took so long. It's just so obvious, you know? A swimming pool that doubles as, wait for it...a floor. Tired of swimming? Feel like walking? Then you need the Hydrofloor.

Basically, the pool's floor slowly moves up and down, either up to ground level (where it's indistinguishable from the surrounding patio) or down, forming a more traditional pool. The best part might be the stairs--they retract from typical stairs into a kind of grooved flat surface.

The pool fills up with...