Sliprannor i Gantofta is a sandstone outcrop near Helsingborg in Scania, Sweden, covered with hundreds of mysterious prehistoric grooves along the Raa river valley escarpment. Once thought to be marks from sharpening weapons, modern scholars have disproven this theory. Current prevailing expert opinion suggests the concave grooves are remnants of Bronze Age sacrificial cult activities, likely imbued with religious or magical significance. Other hypotheses propose stone flour production via spinning wheels or natural erosion from glacial meltwater.
Sliprännor i Gantofta

| Type | Rock relief/carving |
|---|---|
| Period | 1500 - 500 BC |
| Country | Sweden |
| Coordinates | 55.9776° N, 12.8162° E |
Sweden