an area known as "World's End" marks the deepest part of the Hudson, at . Shortly thereafter, the river enters the Hudson Highlands between Putnam and Orange Counties, flowing between mountains such as Storm King Mountain, Breakneck Ridge, and Bear Mountain. The river narrows considerably here before flowing under the Bear Mountain Bridge, which connects Westchester and Rockland Counties. Afterward, leaving the Hudson Highlands, the river enters Haverstraw Bay, the widest point of the river at wide. Shortly thereafter, the river forms the Tappan Zee and flows under the Tappan Zee Bridge, which carries the New York State Thruway between Tarrytown and Nyack in Westchester and Rockland Counties respectively. At the state line with New Jersey the west bank of the Hudson enters Bergen County. The Palisades are large, rocky cliffs along the west bank of the river; also known as Bergen Hill at their lower end in Hudson County. Further south the east bank of the river becomes Yonkers and then the Riverdale neighborhood of the Bronx in New York City. South of the confluence of the Hudson and Spuyten Duyvil Creek, the east bank of the river becomes Manhattan. The river is sometimes still called the North River at this point. The George Washington Bridge crosses the river between Fort Lee and the Washington Heights neighborhood of Manhattan. The Lincoln Tunnel and the Holland Tunnel also cross under the river between Manhattan and New Jersey. South of the Battery, the river proper ends, meeting the East River to form Upper New York Bay, also known as New York Harbor. Its outflow continues through the Narrows between Brooklyn and Staten Island, under the Verrazzano Bridge, and into Lower New York Bay and the Atlantic Ocean. Geography and watershed The lower Hudson is actually a tidal estuary, with tidal influence extending as far as the Federal Dam in Troy. There are about two high tides and two low tides per day. As the tide rises, the tidal current moves northward, taking enough time that part of the river can be at high tide while another part can be at the bottom of its low tide. Strong tides make parts of New York Harbor difficult and dangerous to navigate. During the winter, ice floes may drift south or north, depending upon the tides. The Mahican name of the river represents its partially estuarine nature: muh-he-kun-ne-tuk means "the river that flows both