If your idea of a great vacation means being by the water, visit Dongbaek Island. Whatever you choose to do here, you're unlikely to get bored of those lovely views.
Haeundae, where Dongbaek Island is located, is jampacked with things to see and do. Many visitors also stop by Gwangalli Beach, which is within close reach of the water-surrounded land mass. Have a look around before you move on to your next location.