Plitvička Jezera, a set on Flickr.
Water patiently carves out the limestone and dolomite in the rock, creating caves, stalactites, stalagmites, and lakes in a geography called “karst.”
The water then returns minerals to the rock that turn it into travertine, a porous limestone that changes over time. A couple hundred years from now, the shape and direction of the waterfalls will be completely different.
More significantly, these are some of the best swimming holes in the world, but you’re not allowed to swim in them.