Borough in Grzybowo is one from the biggest ancient cities in Wielkopolska. Its area with embankments and moat has 5 ha. Archaeologists were interested in the borough in Grzybowo since many years. The first archaeologist, who investigated this place was German - Schwartz in 20th century. After the Second World War Polish archaeologist Olgierd Brzeski investigated it again. The borough was built probably at the beginning of 10th century and it was abandoned at the beginning of 12th century. During the researches archaeologists found tools, fragments of dishes and jewellery.