4. Hidden Beach, Islas Marietas, Mexico

Tucked away on one of the Marieta Islands, an archipelago adorning the north-western coastline of Mexico, lies the secluded beauty known as Hidden Beach or Playa del Amor. To reach this secret paradise, one must embark on a boat journey to the island, followed by a unique experience of swimming or kayaking through a water tunnel that connects directly to the vast Pacific Ocean.