People like swimming pools.
Any hotel worth its salt has at least a pool suitable for wading. In most suburbs in America, there's hardly a yard (at least where kids live) that doesn't at least have a kiddie pool. You'll probably never say a bona fide mansion without a pool.
Even in the dead of winter, people like to swim. It is pretty common around here for families to rent hotel rooms just so the kids can swim.
When we took our daughter to Disney World for her 5th birthday present, she loved the parks and the rides, but she would've been happy to swim in our hotel pool (shaped like Mickey's head) for most of the stay if we would have let her.
I could go on.