The most impressive relics in the archipelago are the cairns. These cairns have been built during the Bronze Age and the Iron Age from stones which “a man is able to lift”. The size of these barrows varies, the diameter of some low cairns is a few metres, but some are tens of metres long and a couple of metres high. In the beginning of the Bronze Age, dead bodies were buried in these barrows, but later it became the custom to burn the dead body. In some of the graves, there are jewellery or weapons. In others, there are no artefacts, or they have not been preserved. The Finnish folksy name for these cairns translates literally as “Devil’s sauna stove”.