There was one cannonball still in the moat from a battle with Ivan the Terrible from Russia.
In the courtyard there were indents on the brick wall in the shape of an arch. We later found reconstruction of domed roofed rooms for guards ie shaped like a aircraft hangar.
The young man in charge of the reconstruction explained the problems. The state gives them €10000 per year for the repair which obviously is insufficient but they have recently got some EU funding - ¼ million so will be able to do things to stop further deterioration ie cover the window holes with shutters and put covers over the towers to prevent weather damage.