On its façade have been inscribed 26 inscriptions referring to the citizens of Megara, a fact which led to the secure identification of the monument.
It was a building of the Doric order, made of porous stone, possibly distyle in antis.
Parts of the foundation were maintained, but at a later stage, possibly in the 5th or in the beginning of the 4th century BC, there was erected a second building of a trapezoid plan.
Inscriptions were carved on it, mostly honorary, of which the majority (26 in number) refer to the city and the citizens of Megara.
In 1975–76 the Wall of the Megarians and part of the building was restored at the expense of the Municipality of Megara.