Hokkaidô (literally "North Sea Circuit"), formerly known as Ezo is Japan's second largest island and the largest, northernmost of its 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaidô from Honshû, although the two islands are connected by the underwater Seikan Tunnel. The largest city on Hokkaidô is its capital, Sapporo, which is also its only ordinance-designated city.
The island of Hokkaidô is located at the north end of Japan, near Russia, and has coastlines on the Sea of Japan, the Sea of Okhotsk, and the Pacific Ocean. The center of the island has a number of mountains and volcanic plateaus, and there are coastal plains in all directions. Major cities include Sapporo and Asahikawa in the central region and the port of Hakodate facing Honshû.
The governmental jurisdiction of Hokkaidô incorporates several smaller islands, including Rishiri, Okushiri Island, and Rebun. (By Japanese reckoning, Hokkaidô also incorporates several of the Kuril Islands.) Because the prefectural status of Hokkaidô is denoted by the dô in its name, it is rarely referred to as "Hokkaidô Prefecture", except when necessary to distinguish the governmental entity from the island.
The island ranks 21st in the world by area. It is 3.6% smaller than the island of Ireland while Hispaniola is 6.1% smaller than Hokkaidô. By population it ranks 20th, between Ireland and Sicily. Hokkaidô's population is 4.7% less than that of the island of Ireland, and Sicily's is 12% lower than Hokkaidô's.
