Walk through the water between high canyon walls as a nice way to cool off in Zion National Park. The Riverside Walk Trail is a relatively flat, easy paved out and back trail located at the end of the Zion Canyon Scenic Drive that travels alongside the Virgin River to the mouth of the Narrows. There are water filling stations at the trail head where the shuttle buses drop off as well as restrooms. There are sandy areas near the end near the entrance to the Narrows where you can cool your feet in the cool waters. Go as far as you like up the river but step carefully, as the water can get chest high in some places.