Archaeological surveys on the plateau where the castle stood has disclosed a number of discoveries of artifacts. It was found remains of buildings in the form of both coarse processed stone and more elaborately processed stone, iron objects like nails scissors, keys and knives, and soapstone objects like weights for looms. A special discovery was a silver coin bearing the king's portrait and name. Kong Sverre was the king who minted most coins and is the only one who has placed his name on the coin in this period; REX SVERVS MAGNVS, meaning King Sverre the Great.
It was made new archaeological excavations in 2014 and 2016, this time in the well of the castle. Spectacular discoveries were made. These have attracted both national and international attention! The investigations continue.
So is written in the saga of King Sverre:
"The Baglers took all the goods that were in the castle (Sverresborg) and after that they burned every house that was there. They took a dead man and threw him into the well. Then they threw the stones down until it was full. They called the townspeople out to break down all the stone walls completely to the ground before they left. They burnt all of the king's long ships before they went away. After this they took the road to the Uplands in Sweden. They found that they had acquired many good items on this journey "From King Sverre's saga.
Excavations in the well has revealed a dramatic moment in history. The Baglers had managed to take hold of the castle. They must have been ecstatic. The city's male population was ordered to demolish all stone buildings to the ground level, the other houses were burned. They killed a man and threw his body into the well, where they also emptied all buckets of latrine waste
they found. Then they filled the well up with stone from the demolished buildings.
The detected stones is very interesting. They represents a major source of potential for new knowledge of medieval handcrafts, like the castle’s originally architecture and status, and the connection with the stone masons workshop at the Nidaros Cathedral (the Church of Christ). The findings show that the castle has been a honorable facility with great use of decorative shaped stones.