Green Island (Chinese: 綠島; pinyin: Lǜ Dǎo; Pe̍h-ōe-jī: Le̍k-tó) is a small volcanic island in the Pacific Ocean, about 33 km (21 mi) off the eastern coast of Taiwan. In the 19th century it was known as Samasana Island and the Japanese called it Kasho-to (火燒島). The island is 15.092 km² at high tide and 17.329 km² at low tide. Administratively, Green Island is Lüdao Xiang (綠島鄉), a township of Taitung County and one of the county's two offshore areas (the other is Orchid Island, or Lanyu). Green Island is the ROC's fourth-largest island. It is accessible by airplane landing in the Lyudao Airport in eight to 12 minutes from Taitung City. There are also ferries capable of carrying over 250 passengers.