Ethiopia Holqa Sof Omar is one of the most spectacular and extensive underground caverns in the world. It is over 15 km (9.3 mi) long. UNESCO: The Sof Omar Cave System "represents exceptional geological processes, karstic limestone landforms, and physiographic features ... demonstrating an evolutionary history of millions of years."
Several caves in Spain are sites of prehistoric rock paintings. Approximately when were the earliest, line motifs and stencilled hands, believed to have been painted?
Where are the Mulu Caves, explored since 1978 by a collaboration between UK speleologists, the Forestry Corporation for the area, and the UNESCO World Heritage site which is the Gunung Mulu National Park?
Where is a complex of caves in southwestern France famous for its Paleolithic cave paintings consisting primarily of realistic images of large animals?
