The Sargasso Sea is a region of the North Atlantic Ocean bounded by four currents that swirl around the Bermuda forming a vast whirlpool called the North Atlantic gyre. Unlike all other regions called seas, it has no land boundaries. It is distinguished from other parts of the Atlantic Ocean by its characteristic brown Sargassum seaweed and often calm blue water. The sargassum originates in the nutrient-rich zones close to the coast of the Americas, particularly in the Gulf of Mexico. All of the currents deposit the marine plants which they are carrying into this sea, yet the ocean water in the Sargasso Sea is distinctive for its deep blue color and exceptional clarity. It is also a body of water that has captured the public imagination, and so is seen in a wide variety of literary and artistic works and in popular culture. The Sargasso Sea is frequently (but erroneously) depicted in fiction as a dangerous area where ships are mired in weed for centuries, unable to escape.