The Hidden Waterfalls Trail at Fall Run Park in Glenshaw, Pennsylvania is a difficult 0.4 mile out-and-back trail that leads up a steep hillside to a lookout point with two tall and tucked-away waterfalls with heights of over 50 feet.
The two waterfalls are multi-tiered and cascade down the hillside before merging together in the creek below. The creek then runs west to feed into Fall Run Creek - to where yet another waterfall can be found (viewed from the Fall Run Trail).
The trail is very narrow and climbs a steep rocky slope, which is why the trail is labeled as hard or difficult. Once the trail levels out, you'll notice there's a small spur trail leading downhill to a platform overlooking the waterfall to the south - this is the best view of either of the falls that you'll get. Both waterfalls run heavier in the winter and Spring, so it's possible that these falls are dried up by the Summer.
You can also see the base of the northeast waterfall from the main Fall Run Trail; however you cannot see the southern waterfall from the main trail at all.
At the top of the hill, the trail just ends, but it's possible that you can access Laurelwood Drive if you keep hiking through the woods. When the leaves are not on the trees, you can also get a small glimpse of nearby neighborhoods on the hillsides.
Note: The northeast waterfall is not as easy to see from this trail and the lookout point, which is disappointing, but you can get glimpses of it.