Ключевые слова: abyss, adventure, ancient, beauty, cave, cavern, cold, dark, deep, down, entrance, entry, explore, forest, geologic, geology, green, hole, landscape, moss, mountain, natural, nature, nobody, rock, scenic, secret, sinkhole, speleology, steep, stone, summer, tourism, trail, travel, tunnel, underground, unknown, vegetation, view, wall, wild, wilderness,