Croatia’s largest national park, located in roughly the center of the country, features sheer limestone cliffs that tower above emerald green water and a bounty of large and small waterfalls and cascades that rush down a series of about 16 lakes.
A series of boardwalks at the park takes you around a few of the lakes and waterfalls where you can appreciate the amazing natural processes that create this landscape.
A view from the top of the canyon — you can just barely see the fine white line of the boardwalk trail at the base of the distant limestone cliff face. The highest waterfall in the park is on the right side of the image.
The map of the Plitvice Lakes shows the natural (i.e., not man-made) dams that block the river flow to create the lakes. However, the contours and even placement of the lakes change gradually over time, as the location of dams changes.
Rainfall leaches calcium carbonate from the soft limestone rock and creates channels through the rock to feed an underground river that bubbles up into small ponds and lakes when it reaches harder rock.
The water becomes saturated with calcium carbonate which gets deposited on everything over which the water flows. Vegetation growing along the shore of the lake as well as algae and moss growing at the edge of the lake get a coating of calcium carbonate on them, forming stony barriers to water movement — i.e., dams.
Water flowing over the dams creates cascades and waterfalls that carry the calcium-carbonate rich water further downstream.
More calcium carbonate is deposited on the plants and bacterial colonies creating yet another set of dams and pools above them.
Dams are impermanent structures, because the rushing water dissolves them, only to deposit the minerals elsewhere in slower moving water.
The type of algae that bloom in the calcium carbonate rich waters of the lakes contribute to the unique color of these lakes, which actually change from aqua-colored to teal-colored depending on the season, the temperature, and the algal population bloom.
The lakes are especially beautiful in the fall when the teal green water color contrasts with the rich golds and reds of the forest vegetation.