South Korea is in East Asia, bordering North Korea, and is surrounded by water on three sides, as it makes up the southern part of the Korean peninsula. It is separated from Japan by the Sea of Japan (known as East Sea by the South Koreans). South Korea is mainly mountainous, and there are many islands off the south coast. The capital city, Seoul, is quite close to the North Korean border. The largest island is Jeju Island and the highest mountain is Hallasan, on Jeju. The country is slightly smaller than Iceland and Virginia.