The last thing many mossy Seattleites want to do is hike in the blazing sun. So instead take a gentle one-mile stroll through some majestic old growth until you arrive at the base of Franklin Falls. There the dramatically cascading water throws off a cooling mist, and you can take a swim in the pool below. Back at the trailhead, by a cluster of boulders just off the path, you'll also find a natural waterslide formed by smooth rocks. Rushing water whooshes you down the slide and plops you into the stream?the very, verycold stream. It beats Wild Waves any day. ?Nina Shapiro Exit 47 off I-90, Road 5830 off Denny Creek Road