Nyköping Castle built
1200 CE.
Shown on the map at 58.748°, 17.012°.
Nyköping Castle (Swedish: Nyköpingshus or Nyköpings slott) is a medieval castle, located in Nyköping, from the Birger Jarl era, partly in ruins, mostly known for the Nyköping Banquet which took place here in 1317.
Text from the Wikipedia article Nyköping Castle, licensed CC BY-SA 4.0.