Ostrów Lednicki is the biggest (7 ha) island on Lednica Lake (Wielkopolskie province). In the Piast times, in 920s, a fortified town was created on the island, with a complex of wood and stone buildings of sacred-secular character inside. They have been the subject of the highest protection and investigation of some generations of multi-discipline researchers. Since 1969 the direct care for Ostrów Lednicki is provided by the Museum of the First Piasts at Lednica (Muzeum Pierwszych Piastów na Lednicy). In 1994 the President of the Republic of Poland inscribed „an island – Ostrów Lednicki” on the list of Historic Monuments, which is one of protection forms for monuments bringing a particular value for the culture. Research carried out on the island and in the area of Lednica embrace both archaeological excavations and archaeological-anthropological works, but also underwater, natural and geological research along with non-invasive examining of subsurface structures. Thanks to own publications (Studia Lednickie, „Biblioteka Studiów Lednickich” series) the findings of the research are being made available to broader and broader range of the interested parties. In the activity of the Museum the popularization of archaeology, history and cultural heritage plays a considerable role.