EN
The stronghold in Grzybowo (Września commune, Września county) is among the most mysterious and also the biggest facilities of the type from the early Middle Ages located in the heart of the Piast dominion. It was “discovered” by Olgierd Brzeski who initiated in 1989 excavations continued intermittently by 2009. The research carried out to date allows to define the chronological framework of the stronghold’s existence, namely the time between the 1020s and the mid-1050s. On the other hand, a number of issues like the stronghold’s reconstruction and development, its nature and importance in the Piast domain, its relations with the stronghold network, the course of traffic routes as well as the colony backup facili¬ties and the fortification’s location in the natural environment can and should be investigated in the course of further research.