Here's why:
* Limestone: Limestone is a type of rock that is primarily made up of calcium carbonate.
* Dissolving: Rainwater is slightly acidic due to dissolved carbon dioxide from the atmosphere. This acid reacts with the calcium carbonate in limestone, causing it to dissolve.
* Sinkholes: Over time, the dissolving of limestone creates cavities underground. When these cavities become large enough, the overlying soil or rock can collapse, forming a sinkhole.
Sinkholes are a common feature in areas with karst topography, which is characterized by limestone bedrock.
