These customizable survival - training packages are perfect for anyone craving the adrenaline rush of extreme adventure; and, offer activities such as rappelling high over the rainforest canopy in search of natural shelters, zip - lining through the jungle, tubing down the rivers of underground cave systems and snorkeling among sharks and sting rays at Shark Ray Alley. (breakingtravelnews.com)
Hike through forests, kayak the brightest bioluminescent bay in the world, swim in crystal clear waters, explore Rio Camuy River Park, the third largest underground cave system in the world and so much more. (islandsofpuertorico.com)
The Yucatan Peninsula is a huge limestone platform where fresh water runs like rivers through underground cave systems. (prodiveinternational.com)