Krka in Mid-Morning Sun
Krka National Park, Croatia
The dramatic waterfalls of Krka National Park, Croatia, cascade down a travertine canyon – the largest such formation in Europe. The beautiful formations seen under the water look like rocks or moss, but are actually tufa. Tufa is an iconic part of some mineral springs, like Mono Lake, but can also form in rivers. When a river is low in organic content and supersaturated in calcite, the turbulence of the waterfall can trigger precipitation onto moss or algae. It is said to be a good building material, but the tufa in Krka is now protected from removal.