 Erosion forms of limestone on a rock shelter at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
 Rough eroded limestone rocks in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
 Erosion forms of limestone in a rock shelter at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
 Erosion of a limestone rock at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
 Tree roots and erosion forms on a limestone rock at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
 Rough weathered limestone rocks in Harrarah (Al Kharrarah). Southern Qatar, March 27, 2015
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