The Cleetwood Cove Trail is a difficult 1.7 mile out-and-back trail that leads to the shores of Crater Lake in Crater Lake National Park, Oregon. This is the only hike at Crater Lake that you can take to the water and swim at the lake, so it's a popular heavily-trafficked hike. On the way down, you get amazing views of the banks of the ancient caldera, which is now just the large banks of the lake, Wizard Island, and the surrounding coniferous woodland.
The hike back up is strenuous with many switchbacks along the way, so plan to bring plenty of water. At the bottom of the trail, you can relax along the shores of the lake or go for a swim. There's not a whole lot of room near the bottom of the trail and it tends to fill up fairly quickly as this is a popular hike at the park.