This fascinating abandoned coal mining operation makes for one of the more unusual tourist sights I have seen. Accessible by a 40 min boat ride from Nagasaki. You will have to book a tour to visit. Movement is restricted to three designated viewing areas so the island loses a bit of what would otherwise be a great adventure exploring the ruins.There are no restrooms on the island. Tours are only in Japanese and should be booked in advance. Landing on the island isn't guaranteed and is unlikely in bad weather. The highlight of my visit to Nagasaki.