Documentations

The Oya underground mine in Oya-machi, Utsonomiya has a rich history.

Opened in early 1900, the Oya underground mine in Oya-machi used to be a major source of the popular Oya-Stone. Closed in 1980 and converted into a tourist attraction, museum and performance place, it is an interesting place to visit and learn about its history.

Oya-Stone (Oya-Ishi) is a rock which was created by lava and ash being mixed with water about 20-30 million years ago and became internationally famous as Frank Lloyd Wright used it as material to built the Imperial Hotel in Tokyo.

The miners had a hard time to carve the stone out of the rock, but they managed to create a 60 meter deep, on the highest point 27 meter high and 20,000 square meter in size artificial cave, which has to be seen to be believed. Since the place is enormous in World War II it was converted into a hidden plane factory. Today only 20% of the former quarry is open to the public and the place is often used for art exhibitions, stage plays and concerts with a special acoustic and atmosphere.