As a territory of the United States, Puerto Rico is one of the easiest places to go to rent a villa from Travel Keys. Its proximity to the states as well as a large variety of flight options make Puerto Rico one of the most popular destinations among travelers from the States. One of the sights that is an absolute must see is Puerto Rico's Bahia Mosquito (also known as Bioluminescent Bay) which has one of the highest concentrations of phosphorescent dynoflagellates (a type of glowing algae) in the world. At night this is a spectacular sight to see, and you can actually swim in the glowing water - an experience like no other! Overall, Puerto Rico is a very popular travel destination, and after seeing this, it's no wonder why.