Aleutian Islands, Alaska

a chain of more than 300 small volcanic islands forming an island arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi (17,666 km²) and extending about 1,200 mi (1,900 km) westward from the Alaska Peninsula toward the Kamchatka Peninsula. Crossing longitude 180°, they are the westernmost part of the United States (and technically also the easternmost; see Extreme points of the United States).