Overview:
Sierra Point is a rocky outcropping across from Glacier Point from which there is a view of four waterfalls: Vernal, Nevada, Illilouette, and Yosemite Falls. It is (barely) accessible via a now-defunct trail that connects to the JMT just outside of Happy Isles. It was closed years ago due to rock fall and is no longer maintained, signed, or added to maps. But with a bit of persistence and scrambling you can still find your way there.
Tips:
This is not a casual hike for the inexperienced. Route finding and sturdy footwork is required. But the payoff is worth it!