A long covered hall that ran along the eastern edge of the Altis, separating the sacred precinct from the stadium beyond. Built in the 4th century BC, it took its name from an acoustic phenomenon: a sound made inside could be heard echoing up to seven times. Ancient writers describe it as the "poikile stoa" (painted colonnade), suggesting its walls were decorated with frescoes, none of which survive.
The Echo Stoa served as the boundary between the sacred and the secular parts of the sanctuary. Athletes waiting to enter the stadium walked along it, and it was a gathering place for spectators moving between the Temple of Zeus and the stadium entrance. The long low base of the structure is visible and gives a sense of the scale of what was once a bustling promenade.