Ключевые слова: abstract, adventure, ancient, attraction, background, beautiful, bright, cave, cavern, caving, dark, darkness, deep, formation, geologic, geological, geology, gyokusendo, gyukusendo, hell, hole, japan, japanese, landscape, light, limestone, long, mineral, mountain, natural, nature, okinawa, old, pattern, reflection, rock, rocky, scene, speleology, stalactite, stone, texture, tourism, tourist, travel, underground, view, wall, years,