大谷資料館

Ōya shiryōkan - Oyashi Ryokan - Oya History Museum

Useful Information

Location:	909 Oyamachi, Utsunomiya. Tohoku Expressway, exit Kanuma I/C, 13 km. Tohoku Expressway, exit Utsunomiya I/C, 6 km. Kita Kanto Expressway, exit Utsunomiya/Kaminokawa I/C, 20 km. (36.599989, 139.824745)
Open:	APR to NOV daily 9-17. DEC to MAR Mon, Wed-Sun, Hol 9:30-16:30. Last entry 30 min before closing. Closed 26-DEC to 01-JAN. [2021]
Fee:	Adults JPY 800, Children (6-16) JPY 400, Children (0-5) free. Groups (): Adults JPY 700, Children (6-16) JPY 350. [2021]
Classification:	Rock Mine
Light:	Incandescent Electric Light System
Dimension:	L=150 m, W=140 m, Ar=20,000 m², T=8 °C.
Guided tours:
Photography:	not allowed
Accessibility:	no
Bibliography:
Address:	Oya History Museum, 909 Oyamachi, Utsunomiya, Tochigi 321-0345, Tel: +81-28-652-1232, Fax: +81-28-652-0010.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1919	beginning of stone mining.
1943	Underground secret warehouse for food and clothing of the Army.
1945	underground munitions factory for Nakajima Aircraft (Fuji Heavy Industries).
1969	Government rice storage warehouse.
1979	Oya Museum opened to the public.
1981	first underground concert of the Tokyo Flute Ensemble Academy.
1983	concert 21st Century Prayer from Kitaro.
1984	1st Oya Underground Art Exhibition, artist Kanze school Noh performer Reijiro Tsumura.
1986	quarries closed.
1993	first underground wedding.

Geology

Description

This site is known as 大谷資料館 (Ōya shiryōkan, Oyashi Ryokan, Oya History Museum), but actually it is an underground quarry. The underground stone quarrying at Oya were used for 70 years to quarry Oya rocks. The result are 20,000 m² of underground space. The quarrying went on while the mined out chambers were used as air raid shelter for war production and later as a warehouse. Since 1979 the underground museum is open to the public. Since 1981 underground concerts were held in the caves, including some concerts with Kitaro. Then art exhibitions took place. And since 1993 its possible to get married underground. In the early years there was still quarrying, but the quarry was closed in 1986.

The Oya stone is a layer of volcanic tuff which extends about 8 km from east to west and about 37 km from north to south. The valuable rocks are the middle and upper layers. The rather light greenish stone is very valuable. The mining started with open cast mines, but it was necessary to dig through a thick layer of low quality rock. Then the underground mining started, following the highest quality layers underground.

In the early years the rock was mined completely manual, using hand winches and wooden hoists. The miners were called kodashi. The rocks were carried out of the mine on backpack carriers, each carried stones weighing 150kg. Then wood shavings were used for land transportation and rafts were used for waterway transportation. Rocks were also carried on the backs of horses or on horse-drawn carriages. Most of the Oya stone was consumed around Utsunomiya. Later the quarrying was mechanized, using electric machines, including a winch cableway using an electric motor. The rock was transported to Edo by the water transport of the Kinugawa. Then the railroad increased the amount of rocks. In the 1930s transportation of stones with automobiles started and 1960s it was transported by trucks.