Kern River Slides, Sequoia National Park
Credit: Witold Skrypczak / Getty Images

The waterslides in Sequoia National Park fly a bit under the radar (they're not even mentioned on the park's website), with most visitors coming for the giant trees that the park its name. But don't let the lack of hype put you off. Just north of Johnsondale, California, the slides are fast and easily accessible via a short hike to a tributary of Kern River. The river swells with icy meltwater in spring and early summer, meaning the pools at the end of the slides can be especially brisk. Some portions have formed with dips and rises that allow adventurous types to catch some air before splashdown.