This big boulder of Sortenstenen is found along the beach outside Kalundborg at the Bay of Jammerland. Despite it is a red granite boulder, the name originates from the black algae, covering it.

Location: Asnæs Skovvej 15, 4400 Kalundborg  - and then out to the northern shore by the gravel road. 380 metres to the left at the shore, then 65 metres out in the fjord.
GPS: 55.665845, 11.033424

Size: 1,4 metres high, 4 metres wide and 5 meters long.

Meaning of the name: The black stone.

Material: Red granite/gnejs.

Origin: ?

Legend: According to a legend, the stone thrown by giant Refs on Røsnæs the giant As in Asnæs.
In the stone are traces of the giant's fingers.
According to another legend,  the stone got its black colour after Valdemar the Young's death, which took place nearby in a hunting accident.

Henrik J. Granat from GEUS went around it.