The holiest site of the Ryukyu religion, which is neither Buddhism nor Shinto and was led historically by priestesses rather than priests. You walk a forested limestone hillside of rock chambers, the best known formed by two vast leaning slabs. The inner Sangui area is now closed off and the site shuts for six days a year. Buy the 300 yen ticket at the Nanjo Green Plaza across the road, not at the entrance, which catches people out.