This study focuses on the investigation of geological, geographical, and topographical features of uninhabited islands in the Buan Coast, located between Byeonsan offshore and Sangwangdeung-ri of Wido-Myeon. The islands contain typical coastal geographical and topographical features such as seastack, tafoni, sea cliff, erosion cave, and notch. Geology of the islands consist mainly of sedimentary rocks and volcanic rocks, that indicate the geological history of the islands. This investigation allows the classification of island according to the importance of nature conservation of the islands.