The sanctuary of Zeus Olympios was originally a grove. The first architectural structures were erected in the Hellenistic times. The precinct was surrounded by a wall, partially found. A stoa with propylon in the middle, separated the altar area from the grand yard to the west. Situated in a predominant position to the east of the sanctuary, is the altar of Zeus Olympios, an elongated struture 22 meters long. Built in the 4th century BC, probably over earlier altars. It was made by carved porous limestone and filled with bricks. In front of the altar there were three rows of eleven stone bases. A bronze ring attached to each base, was used to hold the sacrificial animal down.

Inside the sanctuary, stood the statues of the Macedonian kings. Only the pedestral of the statue of Kassandros and a fragment of the pedestral of the statue of Perseus were found. In this same place probably stood the famous sculptures of Lysipos, a group of bronze horsemen, dedicated by Alexander the Great, in honour of those who fell in the battle of the Granikos river in 334 BC.