Gyokusendo Cavern

Gyokusendo is the largest cave system on Okinawa, and the second largest in Japan after Akiyoshido in Yamaguchi.

It is located in the southern part of the island and is part of the Okinawa World Theme Park.

Formed over 300,000 years, there are about 5 kilometers of cave in total, though only less than one kilometer is open to the public.

There are lots of stalagmites and stalactites as well as running water and pools and the whole thing is illuminated with colored lights.