The Green Loop Trail at Settler's Cabin Park in Carnegie, Pennsylvania is an easy 1.7 mile hike featuring a small 4 foot waterfall. From the parking lot, head south at the trailhead and follow the green and blue blazed trail south until you hit a fork in the trail. Take a right-hand turn and continue following the green blazes to reach the waterfall only about 0.3 miles into the hike. The waterfall is fairly small at only 4 feet tall, but it's an interesting slate-rock overhang that protrudes out from the creek. Continue along the green blazed trail up into the hills, past power lines, and then back down toward the Blue Loop Trail again.
This is a great day hike at Settler's Cabin Park near Pittsburgh, PA. You can also hop on the Blue Loop Trail at Settler's Cabin Park along the entire eastern half of this loop.