Bonus: Inwood Hill Park
Besides the foot-trails and roads added by people, the natural landscape of Inwood Hill Park, with its caves, valleys, ridges and primordial forest, has remained largely as it was naturally formed by shifting glaciers. The park contains the last natural forest and salt marsh in Manhattan. However, there is part of Inwood Hill Park was artificially formed. The flat part of Inwood Hill Park, West of the Henry Hudson Parkway and the railroad, was filled in with rocks and dirt from the digging of the subway tunnels for the IND 8th avenue line.