Which sea has no land coastline and lies within the North Atlantic Ocean?

The Sargasso Sea is the only sea defined by ocean currents rather than land boundaries and has no land coastline.

It lies in the North Atlantic Ocean, broadly enclosed by the North Atlantic Current, the Gulf Stream, the Canary Current, and the North Atlantic Equatorial Current. The area is named for Sargassum, a floating brown seaweed that forms extensive surface communities without being rooted to the seabed.

Unlike the Caribbean Sea, North Sea, and Weddell Sea, the Sargasso Sea is not bordered by surrounding continents or islands. Its boundaries can shift because they are based on changing currents rather than fixed shorelines. The region is also associated with the life cycle of European and American eels, which travel to the Sargasso Sea to spawn.