While trees — magnolias, dogwoods, redbuds, pines, towering tulip poplars and oaks, majestic maples and numerous other species — can be seen throughout Atlanta, the forest that existed when settlers drove a stake into the ground in 1839 to mark the rail line's zero-mile post is long gone, with one prominent exception. Fernbank Forest, located on the campus of Fernbank Museum of Natural History, is an intact 65-acre mixed hardwood forest that has survived urban planners, bulldozers, sprawl and — to some degree — even neglect. Fernbank is not unique by virtue of simply being an old growth urban forest. "Every major city in the nation has old growth urban forests," said Robert Loeb, professor of biology and forestry at Pennsylvania State University, DuBois Campus. Several cities, such as New York and Philadelphia, even have multiple old growth forests, added Loeb, who is the author of the book "Old Growth Urban Forests."