Islas Marietas
With crystal clear waters and white sand, no one could imagine that they were used by the government for military tests. Islas Marietas is now protected by the Mexican Government. The Marietas are a group of inhabited islands east from Puerto Vallarta, Jalisco. Water here is so clear you can be seen with 10 meters of depth, but the best part is its reef, swimming in these waters makes you feel at peace, like swimming in a big aquarium.