Metroon (metrôon) was the name given to a building dedicated to the mother goddess, Cybele, Rhea, or Demeter, in Ancient Greece.
The Metroon in the Ancient Agora of Athens was originally used as the meeting chamber of the boule or city council. At the end of the 5th century BCE, when a new Bouleuterion was built, the building was dedicated to the mother goddess. The Metroon also housed the official archives of the city.[1]
Part of the complex of Olympia, and sited immediately below the terrace which houses the Treasuries, is the late 4th/early 3rd century Metroon.[2]