Inside the small forest of Tisvilde Hegn you find an old castle ruin. The castle was founded in the 12th century as part of the Asserbo Monastery. The founder of the monastery was Absalon who also were given Copenhagen as part of his possession and got the title as founder of Copenhagen.
The castle was owned by different noble men for the next few centuries until it was taken over by the king in the middle of the 16th century. During this time the sand were moving significantly in this area following the prevailing winds – and the castle and a nearby village were completely covered in 30 meters tall sand dunes.
The castle was forgotten for a few centuries until it was excavated in 1849 by 12 men from the royal guard. They had to remove 10,000 cubic meters of sand so the castle ruin was once again visible. Finally in 1972 the castle and the moth surrounding it were recreated and the area is now open to the public during their visits to the forest around the castle.
The castle is a nice spot to visit if you are around Tivildeleje and have some transport either a car or a bike. Otherwise you can walk from the beach in Tisvildeleje to the ruin and back but it is a fairly long walk.