On a parapet at the rear of each chamber a single slender Ionic column between two antae supported an Ionic entablature.
The columned, round-headed windows are set in deeply between the pillars which carry the massive entablature, and this again is surmounted by a balustrade with obelisks at each angle and figures marking the line of each bay.
The frieze of the entablature contains sculptures only in the metopes of the east front and in those of the sides immediately adjoining it; the frontal metopes represent the labours of Heracles, the lateral the exploits of Theseus.
While it was probably badly wrecked by the Romans at the sack of the city, its massive columns with the entablature survived.
The fine execution is all that differentiates it from the numerous copies in various museums. The most important sculptures of the Roman period, however, are a group of colossal figures supporting an entablature, a large part of which has been recovered.