City/Regions: Fajardo/Vieques/Lajas. Hidden along the Caribbean coast is one the most spectacular Bioluminescent Bays in the world. The mysterious blue-green light is created by micro-organism which thrive in an environment uniquely suited to their needs. A trip into the bay on a balmy night is a magical experience. Fish flash by in dark water, and a swim is like floating through stardust. This unique bay contains up to 720,000 single-celled bioluminescent dinoflagellates per gallon of water. These half-plant, half-animal organisms emit a flash of bluish light when agited at night. The high concentration of these creatures (Pyrodimium bahamense) can create enough light to read a book from.

.