제주도 is pronounced jeju-do. It is a great island in South Korea, where I went to attend the International Conference on Hybrid Information Technology (aka ICHIT2006). The last day I hiked at volcano 한라산 (Hallasan) with Peter, one of the general chairs of the conference; it was really cold but we had a great moment and interesting talks. I had exceptional views from the plane during my flights between Japan and South Korea.
If you want more information about the area, please check the guide page for 제주도 (Jeju island).