The Dolmens are collective megalithic tombs (dating, in Alentejo, from the end of the fifth millennium BC to the third millennium BC).
The classical Dolmens in Alentejo are composed of a funerary chamber and a narrow passage, opening to the East. The chamber is usually built with seven large vertical stones, supporting a single capstone. These stone monuments were originally concealed by an artificial mound of earth and stone.
The average size of the Dolmens, in Alentejo, is between 2 and 3 meters high, but the biggest one, Zambujeiro, not far from Évora, measures around 6 meters and it is certainly the highest dolmen in the world.
In the Évora district there are registered around one thousand monuments, with different sizes, different preservation status and built with different raw material.