A walk 700 meters from Ilse Made Hotel is that one finds the sacred source to which the hotel has been named. Ilse made is one of Denmark's around 700 sacred sources. In the Bronze Age, the sea lay farther away, and the sacred source served as a well. Today you can see the top of a 3,000 year old, hollow and vertical oak tree trunk that has been drilled into the sand where the source is located. Today's sacred source and the sea have largely gone into one, so the water from there is salty, but on Valborg evening, April 30, it is said to be fresh. The name has been the source after a drowned young woman, Ilse, who flushed on land on the spot. Made means just wet area. The story says that not four horses could drag the body to either Tranebjerg or Kolby, but to Onsbjerg it was easy. Therefore in Onsbjerg Church there is also the golden cross.