On the way from Argos to Epidauria there is on the right a building made very like a pyramid, and on it in relief are wrought shields of the Argive shape. Here took place a fight for the throne between Proetus and Acrisius; the contest, they say, ended in a draw, and a reconciliation resulted afterwards, as neither could gain a decisive victory. The story is that they and their hosts were armed with shields, which were first used in this battle. For those that fell on either side was built here a common tomb, as they were fellow citizens and kinsmen.
Pausanias says that in this battle, shields were employed for the first time. This later remark by Pausanias is indicative of the great antiquity of the structure, as estimated by him and his contemporaries.
The Academy of Athens published results of dating samples taken from the Hellenikon pyramid (9-2-1995). Dating measurements were performed by the Laboratory of Archaeometry at Democritus Research Institute in Athens and by the Nuclear Dating Laboratory of the department of Physics at the University of Edinburgh in Scotland.
The new and experimental method of optical thermoluminescence was employed to date samples taken from the pyramid. It was determined that the samples which had been tested had been quarried at about 2720 BC ± 580 years. The method used, while scientifically sound, has yet to be calibrated. The results, producing a date considered too early for the structure, have not been accepted by the archaeological community. In the absence of a full excavation, the exact dating of the structure will remain unknown. Adamantios Sampson, archaeologist and Ephor of Antiquities, writing in the Magazine Archaeologia kai Technes (December 1995) repeats the accepted line that "the excavational data and our knowledge of the protohelladic period in the entire Greek area exclude the construction of similar edifices in such early years".