In some peripheral parts of Europe, prehistoric menhirs, dolmens, henges, and other megalithic constructions made such strong marks on the terrain that they became integral to the landscape. In the Middle Ages, such monuments were often used as landmarks or boundary markers and, indeed, ended up in coeval descriptions of the territory. In some instances, prehistoric monuments were Christianized to promote the conversion of “pagan” populations; in other cases, they stimulated the creation of stone artifacts - stelae, crosses, standing stones (...) - that might have been used as well as instruments of conversion. The investigation in this article revolves around analysis of the landscape of Sardinia, medieval descriptions of Sardinia’s terrain, and examination of some early medieval stone artifacts there. Parallels found in similar contexts in the British Isles are also considered. (shrink)