Do not use dietary supplements that contain iodine in the place of KI (potassium iodide). They can be harmful and non-efficacious. Only use products that have been approved by the U.S. Food and Drug Administration (FDA).
Mammoth Cave, the world's longest known cave system. The following is a list of the world's 10 longest caves per length of documented passageways. Many passageways are still being discovered; this list is based on the latest verifiable data.he highest concentrations of long caves in the world are found in the Pennyrile of Southern Kentucky, USA, in the Black Hills of South Dakota, USA, and in the Yucatan YucatÃ¡n, Peninsula. mexico
For many years The Lost Sea was considered the world's largest underground lake and is still recognized as the world's second largest non-subglacial underground lake after Dragon's Breath Cave, Namibia. Boat tours of the lake are still given and for many people are the highlight of the tour.