Seoul:

Seoul, officially the Seoul Special Metropolitan City, is the capital and largest metropolis of the Republic of Korea (commonly known as South Korea). Seoul is the world's 16th largest city, and forms the heart of the Seoul Capital Area, which includes the surrounding Incheon metropolis and Gyeonggi province.

Busan:

Busan, a large port city in South Korea, is known for its beaches, mountains and temples. Busy Haeundae Beach features the Sea Life Aquarium, plus a Folk Square with traditional games such as tug-of-war, while Gwangalli Beach has many bars and views of modern Diamond Bridge. Beomeosa Temple, a Buddhist shrine founded in 678 A.D., is at the base of Geumjeong Mountain, which has hiking trails.