The castle in Jasiniec was built in the 14th century by the Teutonic Knights on the site of the former hillfort of Pomeranian dukes. A pfleger subordinate to the Świecie commandry resided there. During the Polish-Teutonic wars, due to the border location, castle often changed membership, moving from hand to hand. In 1454, it finally became Polish and became the seat of the starost. In 1773, the gradually decaying structure was adopted as an evangelical church. On this occasion, ceilings were removed and internal divisions were removed. In the nineteenth century, it was finally abandoned and fell into disrepair.
The castle occupies the top of the hill on the peninsula at the edge of the Castle Lake. It is preceded by a outer bailey, separated by a moat, about 15 meters wide. The castle house was 12,8×22,6 meters in size and was surrounded by a low defensive wall. Its walls were raised to a height of 5,5 meters from glacial erratic stones bonded with lime mortar, and higher parts from brick. The ground floor housed utility rooms, the representational halls were on the second floor, among them the “grand chamber” and the chapel. Above it was a residential level with four rooms. The highest, fourth storey with a defensive function was equipped with 22 arrowslits.
The castle survived in the form of a ruin, deprived of the highest storey and internal walls. It belongs to a private investor, but despite his promises, he has not taken any serious security work so far.
Leksykon zamków w Polsce, L.Kajzer, S.Kołodziejski, J.Salm, Warszawa 2003.