The Echo Stoa is located within the sanctuary of Zeus in Olympia, Greece. It is part of an ancient archaeological site excavated and preserved by the German Archaeological Institute at Athens. A stoa is a covered walkway or portico, typically colonnaded and open to the public. In ancient Greece, a stoa could be used for a variety of reasons including the selling and display of goods, and religious or public meetings. Aside from Delphi, this sanctuary was the most important one in Greece.
Otherwise known as the Stoa Poikile because of the paintings that once lined the hall, the stoa later became known as the Echo Stoa due to the acoustics of its design. It is said one word uttered, would echo seven times. "Almost 100 meters long, it was probably begun after the mid-fourth century, but not completed for a long time thereafter…" It was lined with inner and outer Doric style columns.
Wikipedia https://en.wikipedia.org/wiki/Echo_Stoa
Address 27065, Greece
Coordinates 37°38'18.185" N 21°37'53.906" E