Great Smoky Mountains National Park, Tennessee, United States (© Mint Images/Getty Images)

These mountains were shaped over time long before they became a protected landscape. The Great Smoky Mountains National Park in Tennessee and North Carolina, United States covers over 522,000 acres (more than 200,000 hectares). The park takes its name from the natural smoky haze drifting over its ridgelines. Part of the Appalachian Mountains, these peaks are over 300 million years old.