DeKalb County is located in the north central portion of the U.S. state of Georgia. As of the 2020 census, the population was 764,382, making it Georgia's fourth-most populous county. Its county seat is Decatur.

Fernbank Forest is a 65-acre mature mixed forest that is part of Fernbank Museum of Natural History in Atlanta, Georgia. It has some relatively old trees compared to much of the forests in the Piedmont; as such, it has been extensively studied by scientists. Large specimens of white oak and tulip poplar, which grow up to 156 feet tall, can be found along one slope within the forest. There also are a few equally tall loblolly pine. Other canopy species include American beech, black oak, northern red oak, southern red oak, pignut hickory, bitternut hickory, mockernut hickory, winged elm and red maple. Eastern flowering dogwood, sourwood, umbrella magnolia and eastern redbud are prominent among the smaller trees. The forest floor is covered by many shrub, wildflower, and fern species.