Great Smoky Mountains National Park

Great Smoky Mountains National Park straddles Tennessee and North Carolina in the southern Appalachians. It is America's most visited national park, a UNESCO World Heritage Site, and it charges no entrance fee. The "smoke" is real: the dense forest breathes out water vapor and natural plant compounds that hang over the ridges as a blue haze; the Cherokee called this place Shaconage, "land of blue smoke." The haze shows best in summer, when warm, humid air pulls the most vapor from the trees, on clear mornings especially after rain.