The discovery of three mobiliary art pieces from the 6th millennium BC makes Casa Montero a reference archaeological site for the Iberian Peninsula.  Two of these objects were recovered from shaft 1109.  The first is a fragment of clay showing possible heat treatment, intentional bevelling, and decoration by way of incisions to form a sun motif.  The second is a small, pitted, red quartzite pebble with a representation that suggests a human figure. Finally, shaft 9346 provided a piece of detritic limestone with many incision marks but no evident function. This piece has been interpreted as a stela.  It may be the oldest piece of Neolithic mobiliary art of such characteristics ever found in the Iberian Peninsula. 

Ethnographic studies have suggested that, in many societies similar to that of the Iberian Neolithic, mining activities were associated with magic and rites. These cultural expressions, which are inaccessible to us, could provide a meaning for the mobiliary art objects discovered at Casa Montero.