After starting back climbing last week-end, yesterday I was back caving. We had plnned to go back to Rōkokudō (瀧谷洞) but due to heavy rain weather forecast we changed our plan and went to Ōkubo-no-Kazaana (大久保の風穴). That was for me the opportunity to discover a new cave and practice again caving SRT (Single Rope Techniques).
The cave’s entrance being 100 meters away from the forest road, the access can’t be easier and we start right away with caving. After greeting the cave’s inhabitants at the entrance, we were quickly at the top of the main shaft were a sign says the cave is forbidden to avoid non cavers going further.
After bolting the anchors, we setup two ropes. One to go down directly in the main shaft and the other one crossing it from the top and then down on the other side of the shaft to practice SRT (single rope technique) while going down one rope and back up the other one.
Once back up on the other side of the shaft, we continued our exploration in narrow bowels. And after crawling under a colony of bats that we tried not to disturb, we were walking on all fours in the water.
A water stream goes down this section of the cave creating small waterfalls at the two few meters high steps which require to be secured with a rope. With the noise of the water echoing in the galleries, it creates a very nice atmosphere and it is with some disappointment that we reached the end of the bowel which is getting so narrow that it is impossible to go further. But anyway, it was time to turn around and head back to the exit.
Easy with some shafts that require using SRT caving techniques, the water that goes flows in the bowels, an indeed short length but enough to enjoy a taste of exploration it makes an interesting cave for a one day funny caving trip from Tōkyō. I’ll for sure be back to check the rest of the cave.
The video is available here.
For useful information (access, safety…) about the Ōkubo-no-Kazaana cave, check this article.