Have you ever heard Taki-shugyo? It’s waterfalls meditation which is one of the traditional training for monks.
“Taki”, meaning waterfall, and “shugyo” meaning intense training, is the practice of spirit strengthening by stepping underneath the crashing waters of a fall.
Takishugyo can be used in a few different ways. The first is as an ablution, or cleansing of the spirit. This is most often found in the buddhist religion and was/is often conducted by priests. The waters are said to cleanse away the impurities acrued by the spirit.
Another aspect of Takishugyo is meditation. This is done by certain Zen sects and martial arts groups, including some karate and aikido practitioners (and possibly others, but I don’t know).
As a meditative tool, Takishugyo challenges the practitioner to overcome fierce external stimuli and focus completely on the self. The freezing cold water shocks the body out of its normal state of complacence and invokes many autonomic reactions including gasping, muscle tension, and flight response.
Located 900 meters above sea level, Shukubo Komadori-sanso has served as a shrine lodge for Mitake-jinja Shrine since the Edo Period. Lodges that offer ascetic training are becoming popular among young people, and the waterfall meditation at Shukubo Komadori-sanso is top-notch. The place can reach from Oume station, 1hour 50min from Tokyo station. You will stay one night there and next morning, the owner will take you the fall and shrine. It will be surely special experience. Interesting? Please check it out!