When compared to places like Germany, France, Italy, Spain, England, Austria, the Balkans, etc. Scandinavia seems to have a very apparent lack of medieval castles and fortresses. There are many that seem to be from the gunpowder age still around though. Were there castles prior that were all dismantled/destroyed? Or were castles not as much of a staple in medieval Scandinavian warfare?
2 weeks later, Ive done enough research to answer my own question. For any future look ups, here it is:
Scandinavian fortifications in the middle ages largely depended on the monarch constructing what was, by continental standards, a small stone castle. Often times no more than a fortified manor house. During the 14th century there was an increased use of stone in fortification as Sweden, Denmark, and Norway sought to strengthen strategic places. However, most kings continued to rely on wooden castles.
Even into the 15th century, the designs tended to be old-fashioned, since there was little need for fortifications that could withstand prolonged sieges using the heaviest engines.
One other major reason, was the Nykopings Recess of 1413, which prohibited all fortifications which did not belong to the crown. As a result many existing fortifications were demolished.
Demographic density also played a role. It is a factor often overlooked when discussing construction of large defensive sites. Without people and money, there was neither the need or possibility to carry through large constructions.