Morningside Park and nearby Central Park, Marcus Garvey Park, and Riverside Park. Besides the cliff, one large geological feature that remains is a glacial groove at 121st Street, which had been noted as early as 1916. The western border of the park between 122nd and 123rd Streets is taken up by 36, on a rock drop off; this occupies the former site of the ruins of Blockhouse No. 4, which was used as a source of stone until the park's creation. A tablet was placed on the site by the Women's Auxiliary of the American Scenic and Historic Preservation Society in 1904. Furthermore, part of the cliff was destroyed in 1915. A plateau, on the eastern side of the park, was mostly demolished during the failed Columbia University gym construction project. Today, the site includes a waterfall and a pond, built between 1989 and 1993. The waterfall is artificial and uses water pumped using motors from the city's water system. The pond has been frequented by several species of birds, including great blue herons, night herons, red-winged blackbirds, painted turtles, and mallard ducks. The park also contained meadows when it was constructed. These were at the south end from 110th to 114th Streets; in the central section from 116th to 120th Streets; and at the northeast corner. They were developed as playgrounds and playing fields in the mid-20th century and the rock outcroppings were destroyed. The central and northern meadows were redeveloped as playgrounds while the southern meadow was converted to sports fields. Paths and plantings Morningside Park was designed with many paths and plantings. The paths usually followed the topography, though there are several locations where stone steps connect paths at different locations. There are stone stairs connecting the two portions of 120th Street, and between 116th Street on the west side of the park and 114th Street on the east side. The paths were made originally of gravel, concrete, and asphalt, while the stairs were made of bluestone with rockwork edging on the outer portions. Benches, lights, railings, fences, and stone walls were added over the years; the rockwork edging was replaced. The northern meadow's paths were rebuilt in 1940–1941, while the paths around 36 and the unbuilt Columbia gym were reconfigured or removed in the late 1960s. With the waterfall's construction, the paths at the unbuilt gym site were rebuilt from 1989 to 1993. Some of the