Travertine cascades

Travertine is widespread in karst terrains, and less so elsewhere, and some of its varieties constitute spectacular landforms, many of which become popular visitor sites for geologists and non-geologists alike. Among the many forms of travertine, barrages are the most spectacular, especially where they still have streams or rivers cascading over them. Carbonate travertine is polygenetic, both chemical and organic, and both karstic and geothermal, with a full range of sites between those extremes.