Travertine rock is a form of limestone containing calcite and iron oxides deposited by surface waters such as mineral springs, especially hot springs.  It derives its name from the former town, known as Tibur in ancient roman times.  Travertine  often has a fibrous or concentric appearance.  In limestone caves it can form stalactites and stalagmites. Travertine can form huge natural dams and can build up over several millennia to form waterfalls several hundred feet in height.  A famous example is Plitvice Lakes National Park in Croatia.  In the U.S. examples of this can be seen in the “Hill Country” surrounding Austin, TX and at Turner Falls near Sulphur, OK.  Travertine may precipitate out directly onto rock and other inert materials as most famously seen in Yellowstone National Park where the geothermal areas are rich in travertine deposits.

Travertine is often used as a building material.  The Romans quarried deposits of travertine for building temples, aqueducts, monuments, bath complexes, and amphitheaters such as the coliseum.  Notable buildings using travertine extensively include the Sacre-Coeur Basilica in Paris and the 20th century Getty Center in Los Angeles.  Travertine is one of the most frequently used stones in modern architecture.  It is commonly used for facades, wall cladding, and flooring.