Koonji no Okunoin is a temple located in Saijo, Ehime Prefecture. It's affiliated with No.61 of the 88 Shikoku Pilgrimage temples, Koonji. Here, you can try sitting underneath a small waterfall for 30 minutes, just as monks throughout history have done for ascetic training. It also makes a great picture location!
From Ko-onji, just head south towards the mountains, follow the river southwards. There is a sign visible from route 11. Once you arrive, the parking lot is located directly in front of the rather smaller sized temple. If you are a pilgrim yourself, you can collect an additional stamp here. From the parking lot, its a short walk to the location. The site itself is visible via the walking path between temples 60 and 61 (Yokomineji and Koonji). Try and keep the water raining down on you for over 30 minutes!!