神秘的な雰囲気のある美麗な地底湖 - GIGAZINE
http://gigazine.net/index.php?/news/comments/20080914_under_ground_lake/
行ってみたいがリレミト覚えてないと不安
10 Incredible Underground Lakes and Rivers [pics]?|?Environmental Graffiti
http://www.environmentalgraffiti.com/featured/underground-lakes-river/2190