The Carnegie Trail in Highland Park, Pittsburgh, PA, is an easy 0.2 mile out-and-back hike that connects Reservoir Dr to Lake Dr. Once you reach the bottom of this trail, heading downhill to start, you'll reach Lake Carnegie and the Lake Carnegie Walk, which is a large man-made pond. As of early 2018, Lake Carnegie has been cleaned out and restocked with fish, so fishing here is allowed with a state permit.