This mound (water threshold) is located at one of the lowest point of Philadelphia, 47th and Aspen St. The central part (diameter of 50 ft. , 4ft deep) is built with gravel.
The water flows into this place along the ditch. Water movement is visible in the ditch which is constructed out of semi-permeable material and gravel at the bottom. A waterplay area, lights, a reflection pond and an underground detention basin are set around the mound.
