ダイヤモンドケイブ

Diamond Cave - Iwaya Canyon Cave

Useful Information

Location:	716-0302 Okayama, Takahashi, Bitchucho Fuse. (34.7600180, 133.4504520)
Open:	closed. [2023]
Fee:	closed. [2023]
Classification:	Karst cave
Light:	Incandescent Electric Light System
Dimension:
Guided tours:	n/a
Photography:	n/a
Accessibility:	n/a
Bibliography:
Address:	磐窟渓 - Iwaya Canyon Diamond Cave, 716-0302 Okayama, Takahashi, Bitchucho Fuse, Tel: +81-866-48-3242. Tel: +81-866-48-2200
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

31-JUL-1931	designated a national scenic spot.
1966	cave with speleothems discovered after an explosion.
2010	managment taken over by the municipality.
2010	cave closed due to security issues.

Description

磐窟洞 (Iwayado, Cave With a Rocky Outcrop) or ダイヤモンドケイブ (Daiamondo keibu, Diamond Cave) was operated by the Kawakami Town Tourist Association until 2010, then it was managed directly by the municipality. The first thing they did was actually to close the cave due to several accidents which had happened at the cave. The cave was formerly operated by pensioners and was not very well-kept, but the continually decreasing numbers of visitors made the cave unprofitable. It seems there was no non-profit association and the municipality actually tried to reopen it, what happened then is unclear. Our best guess is that the renovation would have been much more expensive than planned and so the work was postponed indefinitely.

The cave was called diamond cave due to translucent and colourless speleothems, calcite crystals and stalagmites and stalactites, and even helictites. The cave also has the highest stalagmite of Japan which is 2.35 m high. Originally there was a 60 m deep pothole, which was called 天磐窟神社 (Amabankutsu Shrine, Heavenly Pit). In 1966 something happened which lead to the discovery of this 300 m long cave at the foot of the pothole. Most translators translate it with "explosion", but there is no explanation available.

The cave is located in the 磐窟渓 (Iwa iwayakei, Bankutsukei, Rocky Cliff Gorge) or 磐窟谷 (Iwakuru, Rocky Valley), which was cut by the Fuse River. There is a road through the valley which has a small parking lot for five cars, another parking lot with about 25 space is located right above on the Kibi Plateau, about 100 m higher. The cave entrance is halfway up, so it makes actually no difference which parking lot you choose.