The mound, called Eržinkalnis, is located on the highlands, on the left bank of the Lokysta, at its tributary Virkulis. The mound is overgrown with single trees left after felling. There are stairs on the southwest slope. September 24 of 1394 year the description of the Crusaders' road to Medininkai region indicates their "first camp near Lokysta, where there is a castle site". The mound dates back to the I thousand – XIVth c. 19 legends are known about the mound.