It was provided with a double colonnade: the exterior one comprised 29 columns and the interior one 15.
However, it has been associated with the Aetolian League and its increased power and influence over Delphi in the 3rd century BC.
The reason for this might be that it sheltered arms dedicated by the Aetolians as part of their booty after their victory over the Galatians.
A detailed study of the remains offered a fascinating glimpse over the way in which the arms and armours were fastened to the monument in order to be displayed.
[2] There is a general consensus that the building was associated with the deliberate effort of the Aetolian League to be commemorated within the sanctuary through a series of ex-votos and minor monuments established in the site at their instigation.