Japan's longest limestone cave, Akkado in Iwate Prefecture, northeastern Japan, has been found to measure at least 24 km, double the length previously thought, a cave explorers' group says.
Total length of Japan's longest cave found to be 24 km+
The Association for Cave Exploration, a nonprofit organization based in Chiba near Tokyo, said it will present a plan of the cave at a session of the Japan Association of Groundwater Hydrology on May 20 at the University of Tokyo.
The group said it will continue its exploration of the cave, whose total length is believed to be even longer.
The maze-like Akkado cave includes an underground lake which spreads 2 km on the north-south axis and 500 meters on the east-west axis and is at least 140 meters deep, the explorers said.The explorers group, which confirmed the Akkado cave's total length reached at least 12.7 km in 1997, continued its exploration work and confirmed a length of 23.7 km earlier this year.The group's on-the-spot researches totaled 28 rounds in 494 days between 1992 and March this year. A total of 8,451 explorers participated in the work during the period.
The Akkado cave is located in the town of Iwaizumi, some 600 kilometers north of Tokyo. The town is also known for Ryusendo, one of Japan's most famous limestone caves along with Akiyoshido in Yamaguchi Prefecture, western Japan. Iwaizumi uses Ryusendo's groundwater as tap water for residents.
Japan's second-longest cave is the Oyama Suikyodo cave with a total length of 10 km. It is located on Okinoerabu Island, just north of Okinawa.
Text from: Tmcnet.com