Frederikshåb Plantage contains a strange natural phenomenon called the Seven Year Lakes, which some years are water-filled and other years completely dried out.
In 1802, the Danish state established a 1,125-acre birch and spruce tree plantation, Frederikshåb Plantage, on Randbøl Hede. After a century of braving the wandering sands, the heath finally transformed into mature woodland.
In 1999, a hurricane razed a third of the forest and the many forest openings created by the storm have since been replanted with a mixture of deciduous and coniferous trees.
The plantation has a unique natural phenomenon called the Seven Year Lakes in which some of the lakes in the forest dry out in seven-year cycles only to reappear. The plantation also has large woodland sand dunes and a peculiar area with around 175 rock mounds, created 5000 years ago.