These breathtaking lakes in Croatia are truly exceptional, and Plitvice Lakes National Park is one of the world's most beautiful places.

 

They are actually 16 lakes, all interconnected through a series of waterfalls and caves. Each lake is separated from the rest by thin natural dams of travertine, an unusual form of limestone deposited slowly over time from the action of local moss, algae and bacteria. The travertine dams grow at a rate of only 1 centimeter a year, making the lakes extremely fragile.