Hidden Beach

The Marieta Islands by Puerto Vallarta, Mexico,Why it made our list LOOK AT IT While no longer as hidden as the name might suggest, this beach is rumored to have been formed by the Mexican mlitary detonating test bombs in the early 1900s. Think of the street cred youll get by dropping a reference to the secret, underground beach you just got back from vacationing on. Also, theres a water tunnel you have to pass through to get there.