The word "pyramid" denotes the tombs of the Egyptian pharaohs. However, the inordinately large kurgans our ancestors left behind thousands of years ago bring a similar association to mind. The oldest of these is outside Wietrzychowice, near Izbica Kujawska (Włocławek County), on the border of Wielkopolska and Kujawy (Kujavia). Recent arrivals from the Jutland Islands strew the countryside with these enormous and mysterious graves 4,000 years ago. They are over 100 m long, about 15 m wide, and their bases are covered with stones. Archaeologists have uncovered burial chambers at the wider ends of the kurgans. These contain skeletons and are fortified with extra stones. A skull found in one of these chambers bore the traces of having survived four trepanations.

Kurgans that are several centuries more recent can be found around the village of Łęki Małe (Grodzisk Wielkopolski County) in the Obra valley in central Wielkopolska, between Kościan and Grodzisk. These earth and stone constructions are up to 4.5 m high and 45 m in diameter. Today, only four remain along a ridge, although there were 14 in the mid-19^th century. In the mid-20^th century, these massive Obra valley kurgans were dubbed "Wielkopolska Pyramids" by the famous sightseer Franciszek Jaśkowiak.