It's definitely something, and must have required some manpower, being over 7 m and 15 tons. It was "found" in 1965, though it was broken and fallen, and was restored in 1993. It's easy to find from Castelo de Vide, as it is well indicated, as so many other local megaliths.
Castelo de Vide being rich in megaliths, roman and medieval sites, please refer to the Centro de Interpretação do Megalitismo for the nice (and effective!) maps and routes in Northern Alentejo.
Something is not right. This message is just to keep things from messing up down the road