A good little short piece. Much more on a search.
This giant petroglyph hidden under moss was just found in Sweden
Archaeologists were examining a rock slab in a pasture when they noticed a tiny part of a ship under layers of moss.Removing the moss revealed a 15-meter-long petroglyph consisting of 40 figures depicting ships, horses, people and chariots.
The carving is dated to around the 7th-8th century BC during the peak of petroglyph carving in the Northern Bronze Age. source
The impulse to leave a mark is universal, ancient, and wide spread. I was here.