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 all its magnitude, it should be remembered that Mammoth Cave is only one of many large caves in Kentucky. Kentucky is home to another 14 of the longest caves in the world. Prior to 1983, it was 3, but the 50 mile (80 km) long Roppel Cave System was connected to Mammoth Cave and removed from the list.