Kärnan is a medieval tower, the only part remaining of a larger Danish fortress which controlled the entrance to the Baltic Sea.
The origins of the fortress is disputed but Danish legend places its origin to the reign of the legendary King Fróði. However, this legend has not been supported by archaeological proof. Dendrochronological dating has shown that the core was built in the 1310s, when Eric VI of Denmark was King of Denmark. It was considered the most important fortress in Denmark, and was integral in securing control over the strait between Scania and Zealand.
It was surrendered to Sweden along with the rest of Skåneland as part of the Treaty of Roskilde in 1658. The fortress was retaken by Danish forces in 1676 during the Scanian War, and its capture celebrated by flying a giant Flag of Denmark above it. This flag was later captured by the Swedish army and is preserved in the Army Museum (Armémuseum) in Stockholm. The fortress returned to Swedish control by the Treaty of Lund in 1679. Charles XI of Sweden ordered most of it demolished fearing that it was too exposed to a sneak attack from Denmark. The only thing that was saved for posterity was the old medieval tower core. The tower continued to serve as a landmark for shipping through Øresund.
The castle was restored starting during 1893-94, under instructions from Oscar Ferdinand Trapp, a Swedish businessman and engineer (1847–1916). Architect for the restoration was Josef Alfred Hellerström (1863–1931), Helsingborg city architect from 1903 to 1928. The objective of the restoration was to restore, to the extent possible, the appearance the structure had based upon the oldest known medieval illustration. The building's crenellation dates from these repairs.
References:Stobi was an ancient town of Paeonia located near Gradsko. It is considered by many to be the most famous archaeological site in North Macedonia. Stobi was built where the Erigon (Crna River) joins the Axios (Vardar), making it strategically important as a center for both trade and warfare.
Stobi developed from a Paeonian settlement established in the Archaic period. It is believed that in 217 BCE, Philip V annexed Paionia during his campaign against the Dardani who had entered Bylazora, the largest Paeonian town.
The city was first mentioned in writing by the historian Livy, in connection with a victory of Philip V of Macedon over the Dardani in 197 BC. In 168 BC, the Romans defeated Perseus and Macedonia was divided into four nominally independent republics. In 148 BC, the four areas of Macedonia were brought together in a unified Roman province. In the reign of Augustus the city grew in size and population.