Many e-mails are circulating around the web showing great photographs of natural wonders around the
world. Many of these photographs show mountainous scenes from China such as the one below.
This topography is called Karst, and is formed when soluble rock such as limestone is permeated by
acidic groundwater causing a labyrinth of caves and tunnels supported by rocky columns of limestone.
If you have been in a coal mine you will have seen a similar structure underground, where columns of
coal are left as supports. Eventually, the surface collapses leaving only the rocky columns of limestone
and the formation of a Karst topography.