Cruise underground on Oya's magical lake

Navigating by pale yellow lights, boats cruise an underground lake created in a defunct stone quarry in the Oya district of Utsunomiya.
PHOTO: The Japan News/ANN

UTSUNOMIYA - We entered one by one and went down into darkness. After about 150 meters, orange lights suddenly came on. Spread in front of us was an underground lake in a defunct stone quarry in the Oya district of Utsunomiya.

I was taking part in a tour called Ohya Underground, which was launched in 2014 to attract visitors to a former quarry and related sites to which access is usually restricted. Wearing helmets and life jackets, 16 people boarded two inflatable boats before sliding them slowly onto the green surface of the lake.

The boats cruised along, relying on the pale lights set up on the walls made of what is known as Oya stone. The sound of dripping water echoed through the cold air, while the surrounding walls showed their beautiful surfaces. I felt as if we were in an underground shrine.

From 1910, Oya stone was quarried for building materials at this site. After production was shut down in the '70s, rain and underground water accumulated to create an underground lake, with a depth of more than six meters at some points. There are about 250 defunct stone quarries in and around the Oya district, but it is rare for underground lakes to form in them.

I guessed the space spreading in front of us measured about seven meters high, 10 meters wide and 50 meters long.

"In the old days, stone was quarried by hand," said guide Tomoji Kamiyama, 39. "To produce a piece of stone measuring 15 centimeters thick, 30 centimeters wide and 90 centimeters long, a craftsman would strike more than 2,000 times with his pickaxe. One worker was able to produce seven or eight such pieces per day."

How many craftsmen worked to create this vast space and how much did they quarry? I felt wonder at such a stupendous effort.

Fresh reminders

Our boats turned left to cruise deep into the cavern and the ceiling closed in on our heads. We were able to see water droplets on the wall when Kamiyama turned a light on it. "You can see how beautifully and evenly the wall has been pickaxed. This is proof of how skillful the craftsmen were."

Our boats turned to the right and we got off at a landing. Walking on a narrow path for a while, we found natural light coming in from a huge shaft.

We got on the boats again and returned to the starting point of the cruise. Kamiyama then guided us to a place where a number of pieces of Oya stone cut to the same size still stood, along with a rest area for craftsmen with helmets and sake bottles on a table.

Attached to the wall was a piece of paper bearing sayings that it wrongly attributes - though it is a common error - to Keio University founder Yukichi Fukuzawa. One such saying speaks of the joy of having a lifelong job. These items made me feel as if the craftsmen had been working hard, quarrying the stone with their pickaxes, until just a moment ago.

Leaving the defunct quarry, we got on a shuttle bus. Rice paddies, farming fields and trees along the road dazzled me.

"The defunct quarries were long considered a negative legacy," Kamiyama said. "At last, they've come into the spotlight and we have visitors coming here.

"We hope [this trend] will create jobs to help young people come back to Oya."

After the tour was over, I walked around the Oya district by myself and found a ruined building on a hill that had been an amusement facility in the past.

During Oya's heyday in the 1970s, there were more than 100 quarry operators with nearly 1,700 workers. However, the number of these companies has fallen sharply to just a handful today because they faced the rise of cement and challenges from cheaper imported stone.

As dusk was approaching, I went to a bus stop for Utsunomiya Station. The road I was walking along used to have a rail track for transporting stone running along it. No one was standing at the bus stop. I suddenly felt bitterly cold. Crows cawed as they flew back to their roosts.

The Ohya Underground tour is run by Chiikikachi Project, a limited liability partnership established by four local companies. It runs about 10 times a month, only after confirming safety using an observation system featuring seismometers.

A half-day tour costs ¥7,560 (S$93) per person and a one-day tour is priced at ¥12,960 per person, including lunch. For details, visit in Japanese.

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