Britannica Sources used in this answer

Why does Guangxi have so many limestone caves and steep rocky hills?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Karst peaks along the Gui (locally Li) River — Guangxi These towering karst formations near Guilin form one of China's most iconic natural landscapes, having long inspired Tang dynasty poets, Song-era painters, and contemporary travelers alike.

Guangxi’s distinctive landscape of steep rocky hills and limestone caves is the result of a geological process known as karst topography.1

This terrain forms primarily because the region is composed of massive, soluble limestone. The development of these features requires three key conditions: dense limestone near the surface, moderate to heavy rainfall, and active groundwater circulation.12

Because limestone (calcium carbonate) dissolves relatively easily in slightly acidic water, rainwater percolates through horizontal and vertical cracks in the rock, gradually widening them over time. This process creates:2
* Caves and caverns: Formed as water flows along underground cracks, enlarging them into complex systems.12
* Steep rocky hills and spires: Created by the removal of surface material and the deepening of vertical fissures, which leaves behind jagged, protuberant mountains and pinnacles.123
* Sinkholes: Occur when the roofs of large underground caves collapse near the surface.2

These spectacular formations, particularly prominent near Guilin, are part of a landscape collectively designated as a World Heritage site.1