This is not too far from where i live.
A discovery in a peat marsh in Sweden reveals unknown rituals from the Stone Age. Poles with human heads on them had been planted in a pile of rocks in the peat, which was then a pond.
One of the crania was found impaled on a stake at the excavation site. (Photo: Fredrik Hallgren)
One of the archaeologists lifts up a skull. This cranium is attached to a stake. Nobody has seen the likes of this in digs from the Stone Age.
It’s also unusual to find a stone burial mound this old. Burial mounds like this didn’t become common until much later, in the Iron Age from 500 BCE until the Viking era. Its location at the bottom of a little pond is yet another mystery.
Whole Article: http://sciencenordic.com/skull-stake-reveals-unknown-rituals