Cumberland Falls, sometimes called the Little Niagara, the Niagara of the South, or the Great Falls, is a large waterfall on the Cumberland River in southeastern Kentucky. Spanning the river at the border of McCreary and Whitley counties, the waterfall is the central feature of Cumberland Falls State Resort Park, which itself is surrounded by the Daniel Boone National Forest. Under a full moon on clear nights, an elusive lunar rainbow or moonbow is sometimes formed by the mist emanating from the falls.