What are sinkholes? A farmer may view them as naturally forming holds that occasionally open up in the fields. Some people view sinkholes as sites for dumping their trash. In urban areas, the sudden appearance of a sinkhole is a hazard that can disrupt utility services, hamper transportation, and cause severe damage to nearby structures. In anyone's backyard, a sinkhole is a safety risk to the curious who may find it exciting to explore this new "cave." Information about sinkholes in Pennsylvania is pertinent to planning for future land development and for the protection of private and public property. It also provides a fascinating story for those who are interested in learning more about geologic conditions and earth processes.
— From Educational Series 11, Sinkholes in Pennsylvania, DEP

Sinkholes are subsidence features that are the result of water moving residual material and soil through subsurface pathways caused by the weathering process. Sinkholes are typically circular in shape and can vary in size. They show an actual break or hole on the land surface. Sinkholes are found in areas underlain by carbonate bedrock. Click on the thumbnails below to view pictures of some notable sinkholes in Pennsylvania.