The amphitheater under the falls
Shellburg Falls is a gorgeous waterfall right outside of Lyons, OR that has a natural amphitheater completely surrounding it. It's a 5 mile round trip that's starts with about 3/4 of a mile walking through pastures filled with cows and although some might see this as a great picture opportunity, let me warn you those cows were ready to stampede if necessary..
The first waterfall you'll see on your right walking in is a completely vertical drop into a river. I climbed down to the very bottom of the falls but I don't suggest doing this unless you have some bouldering experience to get yourself back up- but I did get some pretty sweet pictures!
Once you get to that first fall there will be a small staircase on your left that's really easy to miss, take this to reach Shellburg Falls Trail. The main falls are completely surrounded by an amphitheater... Meaning you get to walk behind it and through it!
If you're doing this hike during the summer time, definitely bring a bathing suit! There's easy access into the pools and because the water is in direct sunlight most of the day, the water is actually really refreshing! This hike isn't very heavily trafficked, so don't worry about doing it to early in the morning!