Sierra Point is a rocky outcropping in Yosemite Valley that rises nearly 800 feet above the Merced River a short distance from Happy Isle, on the river's north side where it changes from a westerly flow to a northerly one. A maintained trail used to run from Happy Isle to Sierra Point in days gone by, but it has been abandoned and nearly forgotten for many years, much like the Ledge Trail. The steel railing anchored in the rocks still exists at the top, as solid as ever. The entire trail/route is less than a mile starting from Happy Isle, possibly the best short scramble to be found in Yosemite Valley.
The view from Sierra Point is outstanding, and it seems a shame that the trail has been abandoned. It offers what may be the only point where four of Yosemite's five major waterfalls can be viewed simultaneously - Nevada, Vernal, Illilouette, and Yosemite Falls (only Bridalveil can't be seen). One can see nearly straight down to the JMT trail, and the myriad of visitors hiking to the footbridge overlooking Vernal Fall look like tiny ants scurrying below completely unaware of this aerie above.
As an added bonus this provides an excellent view site for observing the aftermath of the huge rockfall from high on Glacier Point that killed one hiker in 1996 and wiped out the Nature Center and Happy Isle (since rebuilt).
From Happy Isle, start on the JMT trail heading towards Vernal Falls. Shortly after passing a sign indicating the start of the John Muir Trail, you'll come to another sign on the left side that says "Rock Piles." If you go straight up through the rocks and stay to the right side of the large talus slide you'll easily find the well worn trail.
Follow what's left of the trail to Sierra Point. There may or may not be ducks to help you, but don't worry if you don't find any. Keep in mind that the route heads generally diagonally up and to the right. If you can't find the trail, or lose it along the way, continue up towards the right and eventually you'll find it again. Having no knowledge that a trail existed, we managed to find it completely by accident, but not until within about 200 yards of Sierra Point. So using the trail isn't really necessary if you don't mind some mild bushwhacking.
Somewhere near the middle of the route the trail has been wiped out by landslides on a particularly steep section. This is the hardest part of the climb, mostly because the ground is loose here. Scramble up and through the steep section (low class 3, a rope may be found to use as an aid) to regain the trail again. This section was probably what led the Park Service to close the trail.