Manhattan is a long, narrow island surrounded by three rivers. The East River borders the east side of the island and separates Manhattan from Brooklyn and Queens.
Separating New York City from New Jersey is the Hudson River on the west side of Manhattan.
And connecting the East River and Hudson River on the northern border of Manhattan is the Harlem River. It separates Manhattan from the Bronx. (And technically it separates part of Manhattan from itself. Marble Hill--though on the mainland--is part of Manhattan.)
And since we're getting technical--here's one for you geological nitpickers. The East and Harlem Rivers are actually tidal straits. But since they're called rivers--that's what they'll be for our purposes.
I could have sworn I had photos of the Harlem River--but I can't find them! Eight miles long with fourteen bridges. The wikepedia entry has a few good photos.
Taken on the subway crossing from Brooklyn to Manhattan:
The view from hubster's hospital window. Looking over to Brooklyn.
See that structure in the lower part of the photo? That's the Water Club--one of my favorite restaurants. And here's the view from inside the Water Club.
Taken in northern Manhattan. The view is looking south.
At the 79th Street Boat Basin. You can see the George Washington Bridge in the northern distance.
Taken from a water taxi pier in New Jersey looking across to Manhattan.
Looking over to New Jersey from Manhattan:
The Hudson River flows north to south for 315 miles. Albany is on the New Jersey side of the river. That's Rensselaer, NY on the other side of the river.
The Hudson River begins in the Adirondack Mountains. This is the river at Newcomb, NY. That's about ten miles from the source of the Hudson's headstream in Lake Tear of the Clouds.
There was lots of celebrating along the Hudson River in 2009 since it marked the 400th Anniversary of Henry Hudson discovering the river.
****Still trying to catch up with the ABC Along. My ABCs focus on NYS/NYC things.