Li River, China

City of Guillin

Pictures by: Father Tomas Del Valle-Reyes

These strange hills are what makes the Li River so famous. Karst Hills is a geologic term that describes geologic formations subject to forming caves and sink-holes. Limestone and gypsum are typical materials that makeup these kinds of formations.
Li River, China They dissolve easily in water. Over time the ground water will migrate in an underground stream carrying the dissolved material along with it. Eventually caves will form, then sink-holes if the cave ceilings give away.

Take this idea to the extreme and you will find that these strange hills are what is left after so much of the rock has dissolved and been carried away. Li River, China As we move down river, in a beautiful cruise, you will see several waterfalls, mountain peaks so high and low giving you an expectacular view of heaven. These underground streams continue to gnaw away at the inside of these hills. Eventually, of course, these hills will be completely eroded away, and the area will be a plain.