Petroglyph, Boat-Axe culture, pre-Viking, Vitlycke, Bohuslan, Sweden, Bronze Age. Vitlycke is one of the largest surfaces of rock carvings in the whole of Scandinavia. An enormous snake coils towards a man with his arms in the air. This images has been interpreted as sacrifice scene, depicting a priest and cult animal, and the battle between Thor and the serpent Midgard.