FOR TRAVELING FAMILIES with a full itinerary, a stop at the playground can feel like more work than fun. Sometimes the swing sets and twisty slides begin to blend together whether they’re in Buffalo or Budapest. Unless you’ve happened to stumble upon one of the world’s greatest playgrounds. Thanks to the playful imaginations of innovative architects, the days of squeaky seesaws and drab jungle gyms are giving way to outrageous designs and accessible environments that spark young imaginations. Here are 12 standout playgrounds that will delight the whole family.