You can find Trelleborg between Tudeaa and Vaarby Aa (streams on Zealand), and it was the first Danish Viking castle discovered.
You can see from the building that is was constructed in about 950.
The castle was dug out in 1934-1941, and the way the castle was built was surprising, because the Danes untilll then didn’t know about that kind of building technique.
The circular earthwork which surrounds the castle is 137 meter in diameter.
Trelleborg has gates from the four points of the compass.
Near the forecastle there is a graveyard with 135 graves including a mass grave with 10 skeletons, and it’s probably the result of fights in Trelleborg.
There is a little disagreement about Trelleborg’s function, but archaeologists agree that only a king could build the castle. The king at that time was Harald Bluetooth, and he probably constructed the castle to save the Danish kingdom.
Today Trelleborg is restored so you can have a general view of the building.
If you want to know more about Trelleborg, you can visit the museum and see some of the excavations.
But do you want to know more of one of the others castles you can visit this homepage: (but it is in Danish).