What and where is it?
The Northwest Passage is a sea route through the Arctic Ocean, connecting the Atlantic and Pacific Oceans.
From West to East the Northwest Passage runs through the Bering Strait (separating Russia and Alaska), Chukchi Sea, Beaufort Sea, and then through several waterways that go through the Canadian Arctic Archipelago.
In the video on the left, director and producer Sprague Theobald shoots a video of an ice field in the Northwest Passage.
There are also good photo galleries of the Northwest Passage in Picasa and Flickr - links here and here.