The construction of the castle in Gosławice can be combined with the Poznań bishop Andrzej Łaskarz, who began to build his residence around 1418. The castle together with the village later belonged to many Wielkopolska families. Archaeological research shows that it was destroyed during the Swedish Deluge, and at the beginning of the 19th century, the ruined building became part of the farm and was partially converted into a brewery.
The castle was built on a narrow sandy sandbank from the west bordering swampy wetlands, and from the north with the waters of the lake. From the south, access was also hindered by swamps and probably the moat, while from the east there were no major natural obstacles.
Originally, the brick castle consisted of two parallel two-storey and two-room (on each floor) houses, connected by a third, short wing on the southern side and a curtain of the wall to the north, closing the inner courtyard with a width of 8 meters. The whole four-sided layout was 22×25 meters. Arrowslits in the outer walls of the houses testify to their defensive character, although the whole complex was towerless. Both main buildings had two floors and a basement, with an underground dungeon operating under a short southern link. The gate was in the short northern curtain.
In in the first half of the 15th century there was the second phase of the castle expansion. A quadrangle of external walls was created at the time, measuring 38×42 meters and a height of about 4 meters, separating the undeveloped area of the zwinger. In the corners of the new perimeter wall, suspended, cylindrical turrets with an internal diameter of 3.6 meters were erected, probably connected to the wall-walk, which was based from the zwinger side on arcaded recesses. The wall thickness varied considerably: from 1 meter (north and west curtain), through about 1.4 meters (south curtain) to 2.3 meters from the most endangered side (eastern curtain). The whole was surrounded by a moat, over which a dansker (latrine) was added on the southern side, to which a timber porch led. The outer gate was also placed on the north side. It was preceded by a drawbridge based on four pillars, two by the inner perimeter wall and two by the outer defensive wall on its inner side.
The castle, renovated in the post-war period, consisting of a perimeter wall and two whitewashed, two-story buildings is now the seat of the District Museum in Konin. In the gothic cellars there is a permanent and temporary archaeological exhibition, and in the upper rooms, among others are exhibitions depicting the history of Konin.
Leksykon zamków w Polsce, red. L.Kajzer, Warszawa 2003.
Olejniczak K., Grody i zamki w Wielkopolsce, Poznań 1993.