Places known for their prehistoric petroglyphs are often named after the carved images and symbols found there. Focusing on a corpus of 115 representative toponyms from the Spanish, Galician and Portuguese speaking areas, the present article explores the interaction between the lexical components of place names and the rock carvings to which they refer. This analysis allows us to distinguish between several types of name motivation and to explain the manner in which such enigmatic testimonies of past cultures were perceived and interpreted before they became the subject of scholarly research.