Cool Springs Environmental Education Center (CSEEC), owned by Weyerhaeuser Company, includes a 591 ha State Significant Natural Area. It is located in Craven County, North Carolina, in the floristically rich Atlantic Coastal Plain. A vascular flora inventory documented the occurrences of 567 species and sub-specific taxa and 303 genera in 118 plant families, including populations of the Atlantic Coastal Plain endemics Pondspice (Litsea aestivalis) and LeBlond's Coastal Goldenrod (Solidago villosicarpa). We identified twenty plant community types, including the uncommon Longleaf Pine (Pinus palustris) Woodland, Bald Cypress–Tupelo Gum (Taxodium distichum – Nyssa aquatica) Swamp, a number of small depression wetland communities, and the novel Sand Laurel Oak-Loblolly Pine (Quercus hemisphaerica – Pinus taeda) Woodland. Soils ranged from excessively drained sands to very poorly drained organics. The order of the soil mapping units according to the number of plant taxa they supported per unit area was TaB > PO > Ln > Mu > DO, MM > Se > KuB. Among five of 12 floristic study sites having positive residuals in the regression of log species richness on log area, CSEEC had the third largest residual. There was no relationship between the residuals from regressions of log species on log area and soil drainage heterogeneity on log area. The occurrences of two rare plant species, a species-rich flora, ten natural plant community types, and an assemblage of wet and dry soils in a variety of geomorphic settings are objective factors justifying the recognition of CSEEC as a State Significant Natural Area.