magical bridge into akiyoshi cave

adventure akiyoshi akiyoshido akiyoshidou ancient asia attractive august beautiful beauty bridge brook cave cavern covered creek dark destination earth evening geology historic honshu iconic ina inagawa inakawa japan japans karst largest limestone mine monument mystic natural nature park past prefecture pretty river rivulet rock scenic science solutional special speleology stone stream summer takes this time tourist tranquility travel underground view visitors walkway water waterfall yamaguchi