There are multiple falls along the hiking trails in the area. The first few falls are close to the entrance and easy to access. They’re a bit smaller, but often overlooked. Traveling further, you can get to the fall that is in most of the images (Caveman Falls, or Twin Falls.) This pool is much larger, and usually more crowded than the previous falls. It’s a bit more difficult to access and a further hike. If you want to visit it, stay on the main path, and turn left when opportunity arises. You’ll have to scramble across the river stones for a bit, then you’ll come to the falls.
Make sure to be very careful at any falls. Swimming under a waterfall is something you may dream about, but natural debris from up stream has been known to flow down falls and injure or kill people. Swimming near a waterfall is just as good as being directly under it. The danger of flash flood is also an issue. It’s very difficult to know just how much it’s raining miles up stream. So use your head and be safe.