Ключевые слова: ancient, asia, attraction, background, bridge, cave, cavern, caving, cliff, dark, deep, entrance, europe, exploration, forest, formation, geologic, geological, geology, grotto, hole, inside, interior, landmark, landscape, light, limestone, mineral, moss, mountain, national, natural, nature, old, park, passage, rock, scenic, speleology, stalactite, stalagmite, stone, tourism, travel, tunnel, underground, view, wall, water, wild,