洞穴迷宫 Caves
The Earth's large, deep calcareous caves are virtually inaccessible and therefore barely explored - requiring expert diving where flooded. Some of its wildlife is as strange and specific as in the deep, darkest part of the ocean, whether physically adapted -notably to the dark. Nevertheless, some caves(did) play an important part in native cultures, even as sources of fresh water for some Mayan cities.
墨西哥的燕子洞立起来有400米深,足以放下整个帝国大厦;美国的龙舌兰洞穴系统有193米长,500米深,而且洞内悬挂着让人惊异的晶体结构。洞穴的神秘、不寻常之处通常不被注意,其实那儿同样生活着一些奇异的野生生物:洞穴天使鱼通过扁平的鳍上所生长的精微的钩状物使自己悬挂在洞穴瀑布后面的壁上;洞穴金丝燕通过声纳系统导航,用唾液建筑精美的巢;得克萨斯的洞穴火蜥蜴既没长眼睛也没有色素,让人惊奇的是它们怎样在这个到处都是钟乳石、石笋以及穴居生物的隐秘世界长期的生活着……