Supporting the fort were numerous defenses. Batteries were placed on Jeffrey's Hook, which extended into the Hudson, on Cox's Hill looking over Spuyten Duyvil Creek, at the north end of Manhattan controlling the King's Bridge and Dyckman's Bridge over the Harlem River and along Laurel Hill which was to the east of the Fort and went along the Harlem River (see also "Fort Tryon Park"). To the south of the fort were three lines of defense. The lines went through the hills and were made of trenches and foxholes. The first line was supported by a second line about 0.33 mi (0.5 km) to the north, and a third line was planned to be built 0.25 mi (0.4 km) north of the second.