Western Hemisphere

The Western Hemisphere is a geographical term for the half of the earth that lies west of the prime meridian (which crosses Greenwich, UK) and east of the antimeridian, the other half being called the Eastern Hemisphere.
In this sense, the Western Hemisphere consists of the Americas, the western portions of Europe and Africa, the extreme eastern tip of Russia, numerous territories in Oceania, and a portion of Antarctica, while excluding some of the Aleutian Islands to the southwest of the Alaskan mainland.