Political map of Australia, New Zealand & the Southwest Pacific 6 September 1942 (Kokoda Trail): Unable to take Port Moresby by sea (Battle of the Coral Sea), the Japanese attempted to reach it by crossing New Guinea's Owen Stanley Range via the narrow and steep Kokoda Trail (Kokoda Trail campaign). There they were met by the Australians and for months the two sides fought back and forth over some of the most extreme terrain in the world, before American successes on Guadalcanal (Guadalcanal Campaign) forced the Japanese to abandon their efforts.