2,700-year-old petroglyphs found on mossy rock in Sweden

Archaeologists have discovered a group of late Nordic Bronze Age petroglyphs hidden under a thick covering of moss in Bohuslän, southwestern Sweden. Forty figures, including 13 ships, nine horses, seven people and four chariots, cover an area fifty feet wide. It is the largest find of Bronze Age petroglyphs made so far in this century.

The rock was found on pastureland at a farm in the parish of Kville. When the figures were carved 2,700 years ago, the site, now 40 feet above sea level, was on the coastline. The rock was on an island and was partially submerged. The artists must have stood on boats to carve the artwork just above the waterline. The petroglyphs would have been highly visible in the seascape.

Some of the individual carvings are notably large. One of the ships is 6.5 feet wide; one of the humans is more than three feet tall. The engravings are deeply carved, exposing the white rock and standing in sharp contrast to the grey of the background, long-since darkened to a charcoal color by the cyanobacteria in the sea water.

Archaeologists from the Foundation for Documentation of Bohuslän Rock Carvings spotted a small piece of one of the ships peering out from the thick moss cover. When they removed the moss, they found a wealth of other petroglyphs carved into the nearly vertical surface of the stone. That’s an unusual alignment; usually the petroglyphs were engraved on flatter slabs that the artists could easily climb and stand on to carve.

This orientation gave archaeologists the ability to date the work with more precision than is usually possible. Because we know what sea level was at different periods, the rock art cannot have been carved before the 8th century B.C. when the stone emerged from the lowering waters. If it was carved after the 7th century, the artists would have had to use ladders to reach the rock face, and carving in straight lines for meters while on a ladder/platform is prohibitively challenging, if not impossible.

The province of Bohuslän on the rocky coast of southwestern Sweden consists of more than 8000 islands and islets. More than 1,500 rock art sites, the largest concentration of Bronze Age rock art in Scandinavia, have been documented there, and that is a fraction of the estimated total. Historically most of the focus has been on the art found on the more grand cliffs and outcroppings as documenting all of the rock carvings was deemed an impossible goal. The Foundation for Documentation of Bohuslän Rock Carvings has been working for more than 20 years to seek out previously unknown petroglyphs and to document them in a systematic way.