The meridian 80° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Atlantic Ocean, the Caribbean Sea, Central America, South America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole.
In Antarctica, the meridian defines the western limit of the British territorial claim and passes through the Chilean claim - the two claims overlap.
The 80th meridian west forms a great circle with the 100th meridian east.
From Pole to Pole
Starting at the North Pole and heading south to the South Pole, the 80th meridian west passes through: