The largest flat rock of Nordic Bronze Age petroglyphs in Scandinavia, the Vitlyckehäll, is located in Tanumshede. It was discovered in 1972 by Age Nilsen, who was originally intending to place an explosive charge for construction work.
In total there are about 3000 Tanum petroglyphs, occurring in about 100 panels. These are concentrated in five distinct areas along a 25 km stretch, which was the coastline of a fjord during the Bronze Age, and covers an area of about 51 hectares (126 acres or 0.5 km²).
Scandinavian Bronze Age and Iron Age people were sophisticated woodworkers and very competent travelers by water. (Dates for ages vary with the region; in Scandinavia, the Bronze Age is roughly 1800 to 600 BCE) Some of the glyphs depict long boats of the Hjortspring boat type carrying around a dozen passengers. Wagons or carts are also depicted.
One glyph depicts a hunter with a bow, and others depict hunting scenes. Some of the stone pictures show people performing agrarian tasks. There is a human at a plough drawn by two oxen, holding what might be a branch or an ox-goading crop made of a number of strips of hide.
The rock carvings are endangered by erosion due to pollution. To the dismay of some archaeologists, they have been painted red to make them more visible for tourists.