In the late 3rd century BCE the north-west corner of the stadium was linked with the sanctuary through a narrow roofed corridor.

Towards the mid-5th century BCE the stadium was moved 82 m to the east and 7 m to the north (Stadium III). Excavations have shown that the embankment of the narrow western side was truncated after the mid-4th century BCE, when the Echo Stoa was built, which entirely separated the stadium from the sanctuary. The track of this new stadium was 215.54 m long and about 28.5 m wide. The banks that enclosed it on four sides could accommodate 45,000 spectators, most of whom would sit on the sloping ground, the few stone seats being kept for dignitaries. The stone exedra for the Hellanodikai was opposite the Altar of Demeter Chamyne. In the late 3rd century BCE the north-west corner of the stadium was linked with the sanctuary through a narrow roofed corridor.