Even without the world's longest cave system, the land encompassing Mammoth Cave National Park would merit its National Park status due simply to its extraordinary density – and diversity – of plant life. While the acknowledged 'showcase of vegetation' within the Park Service, Great Smoky Mountains National Park, has approximately 1,500 flowering species in its more than 500,000 acres, Mammoth Cave National Park supports more than 1,300 species in only one-tenth of that acreage.