Ключевые слова: adventure, alone, ancient, backpack, black, cave, cavern, caving, corridor, dark, darkness, deep, earth, entrance, exploration, extreme, geologic, ground, hole, human, inside, lamp, light, mountain, mystery, natural, nature, night, old, one, people, person, ray, research, rock, rustic, shadow, spelunker, stalactite, stalagmite, stone, torch, travel, underground, walking, wall, woman,