Ziplining is all the rage these days. And with the exhilaration, scenic smorgasbord, and novelty factor, we can see why. Treetop Trekking's Barrie site has a course for kids as young as five—and that's in addition to the six other courses for 'big' kids (ahem. Mom.) The kid courses feature bridges, hammock nets, balance logs and more, with more advanced courses that are suitable for ages 9 and up. But if the tykes are really ready for the zipline—well, head over to the Elora skyrider zipline, where kiddos as young as three can take a turn.