My favorite campground in the Angeles National Forest. Easy hike in, a little over 2 miles, and the spring is almost always running. You don't even need to filter the water. It can be a popular spot so he developed campsites may fill up quickly, but there are plenty of places to put up a tent all around. Hike up to Mt Islip and enjoy the views on a clear day. If the PCT hikers are coming through, it will be very crowded though.