The well-preserved earthen structure, which is visible, inter alia, from the road from Bobrowo to Wichulec, undoubtedly adds to the beauty of the area.

History

Based on the pottery fragments obtained in the course of archaeological surveys, it has been concluded that the feature saw three distinct periods of habitation. The first period of habitation, most likely before the establishment of the hillfort, is dated at the 9th century and the first half of the 10th century. The second period of habitation is dated at the second half of the 10th century and the early 11th century. The third period of habitation is dated at the 12th century.

Description

The hillfort is located on a small peninsula by the northern shore of Lake Oleczno. The feature is situated outside built-up areas, roughly 200 m south-east of the road from Bobrowo to Wichulec.

The hillfort is a single-component feature in the shape of an elongated oval. The longer diameter of the hillfort runs along the north-south axis and is roughly 100 m long at the rampart base while the shorter diameter on the east-west axis is roughly 70 m long. The height of the hillfort ramparts compared with the surrounding area is roughly 5-7 m. The size of the inner yard cannot be determined with certainty due to erosion of the slopes of the rampart, but the dimensions are estimated at 25 m × 40 m. The hillfort is overgrown with grass and other scrub vegetation, with only a few small trees on the external slope of the norther part of the rampart, which is why its form is clear and visible from several metres away.

Archaeological excavations were performed in 1974, 1986 and 1992. In 1974, they were carried out by Andrzej Kola and Gerard Wilke. They made two excavations located in the central part of the inner yard and at the junction between the inner yard and the rampart. One of the excavation measures 4 m × 4 m and the other 4 m × 8 m. 71 pottery fragments and animal bones were collected during the excavations. In 1986, the excavations were headed by Kazimierz Grążawski. At the time, an area of 100 m2 in the northern part of the hillfort was examined through five excavations, of which three measured 5 m × 5 m, one 10 m × 2 m and one 5 m × 1 m.  1,667 pottery fragments and animal bones were collected during the research. In 1992, the research was also led by K. Grążawski; at the time, one excavation measuring 2.5 m × 4 m was made and 104 pottery fragments and animal bones were collected.

The archaeological research yielded information on how the feature had been used. The thickness of the revealed cultural layers was up to 3.5 m. In the layers dated at the first period of habitation, remnants of two earth lodges were discovered recessed roughly 0.8 m into the undisturbed soil, i.e. sand in this case. In the layers dated at the second period, signs of damage in the form of burnt material and overground wooden structures were discovered and it is believed that one of them might have been a gate. There were also remnants of three half-earth lodges and a hearth. The layers dated at the third period of habitation contain feature signs of damage, including burnt material and pieces of charcoal, which are believed to be remnants of internal buildings.

The monument is open to visitors. Moveable artefacts recovered during the archaeological excavations can be admired at the Brodnica Museum.

Prepared by Leszek Kotlewski, National Heritage Board of Poland, Regional Branch in Toruń, 18-12-2014

Bibliography

• Boguwolski R., Kurzyńska M., Archeologia północnej części ziemi chełmińskiej, Grudziądz 2001.
• Grążawski K., Bobrowo, [in:] Wczesnośredniowieczne grodziska ziemi chełmińskiej. Katalog źródeł, pp. 35-41, Toruń 1994.
• Grążawski K., Kasztelania świecka i michałowska. Studia nad kształtowaniem się struktur państwa piastowskiego na pograniczu polsko-pruskim, Włocławek 2005.
• Zielonka B., Zabytki archeologiczne województwa bydgoskiego, Bydgoszcz 1959.