Gyokusendo is a limestone cave in Okinawa Prefecture Nanjo Tamaki character Maekawa.
March 1967, Ehime result of academic exploration section is investigated, in its entirety has been revealed for the first time.
In April 1972, it was published as for tourism by Nanto Corporation.
Now it has become one facility of “Okinawa World Cultural Kingdom of Tamaizumihora”.
Reference : 玉泉洞(Gyokusendo) – Wikipedia (Japanese)
Icicle stone is growing at the speed of 1mm in three years. ,
Would the time has elapsed how much is to this length can be.