Jejudo (also known as Jeju Island) is the largest island off the coast of the Korean Peninsula, and the main island of Jeju Province. The island lies in the Korea Strait, southwest of South Jeolla Province. The island contains the natural World Heritage Site Jeju Volcanic Island and Lava Tubes. Jejudo has a temperate climate; even in winter, the temperature rarely falls below 0 °C (32 °F).
Historically, the island has been called by many different names including:
Before the Japanese annexation in 1910, the island was usually known as Quelpart to Europeans. The name apparently came from the first European ship to spot the island, the Dutch Quelpaert, which sighted it after being blown off course on its way to the Dutch trading base in Nagasaki, Japan, from Taiwan (then the Dutch colony of Formosa).