Which peninsula is divided between North Korea and South Korea?

The Korean Peninsula is divided between North Korea and South Korea.

It extends southward from northeastern Asia between the Yellow Sea on the west and the Sea of Japan, also called the East Sea in Korea, on the east. The Korea Strait separates its southern end from Japan. The peninsula's terrain is largely mountainous, with the Taebaek Mountains forming a major eastern range.

Following Japan's defeat in World War II in 1945, Korea was divided near the 38th parallel into Soviet and American occupation zones. The Korean War began in 1950 and ended with an armistice in 1953, not a peace treaty. The Demilitarized Zone now crosses the peninsula near the military demarcation line. Jeju Island lies south of the mainland peninsula and is part of South Korea, but it is not itself part of the peninsula.