Dutch Harbor is located in the Aleutian Islands on Unalaska Island. The commercial fishing fleet berthed here is responsible for the pre-eminent catch, in terms of quantity and quality, of the nation's ports. The area's 18th century Russian past is reflected by two stately Russian Orthodox churches. Dutch Harbor's participation in World War II, beginning with a Japanese air attack on June 2, 1942, is reminiscent in an impressive array of weathered military sites, concrete pillboxes and bunkers. Eleven military installations consisted of the Dutch Harbor Naval Base, and other facilities required for harbor protection and support.