The Bluegrass State Land for Sale; Kentucky is a state located in the east south-central region of the United States. Kentucky is known as the "Bluegrass State", a nickname based on the bluegrass found in many of its pastures due to the fertile soil. It is a land with diverse environments and abundant resources, including the world's longest cave system, Mammoth Cave National Park, the greatest length of navigable waterways and streams in the contiguous United States, and the two largest man-made lakes east of the Mississippi River.