Petrified dunes are ancient sand dunes that have undergone a process of fossilization, turning the once loose sand into solid rock. This transformation occurs over millions of years as minerals seep into the sand, filling the spaces between grains and eventually hardening into stone. The result is a unique geological formation that preserves the shape and structure of the original dunes. These formations can be found in various locations, often in desert regions where wind and erosion have shaped the landscape. One notable example is the Petrified Dunes in Zion National Park, which showcases stunning colors and patterns, attracting geologists and nature enthusiasts alike.