Evidence of human presence in Asturias goes back to the early Palaeolithic period around 100.000BC. From a touristic point of the view some of the most appreciated evidence of this human presence is the Palaeolithic art dating from 35,000 to 4,000 B.C. Original paintings can still be seen in the spectacular caves of Tito Bustillo at Ribadesella and smaller examples in the caves of El Buxu and El Pindal. The Neo cave in Altamira (Cantabria) has very good replicate paintings, as the original paintings can no longer be visited by the general public.
In Asturias there are the remnants of various hill forts or "Castros" from the Iron Age, The Castro de Coaño is a magnificent example and well worth a visit if you are in the area.
Finally there are various tombs and dolmens in Asturias, which can be visited.