Location: Northwest of the Monument of the Eponymous Heroes in the plan of the Agora of the Guide: Mc CAMP II, J., The Athenian Agora: A Short Guide to the Excavations, Excavations of the Athenian Agora, Picture Book no 16, American School of Classical Studies, Princeton 2003, pp. 2 and 24-25.
Date of Construction: 4th century. It is relocated to the Agora of Athens during the reign of Augustus. 
Periods of Use: Roman.

The graceful marble temple, which was probably connected with the worship of Zeus Agoraios, was relocated to the Agora, together with three temple-like structures (SW Temple, SE Temple, and the ‘Temple of Ares’), during the early Imperial period, from an unidentified location in Attica.  Its original construction dates to the 4th cent. BC.

The monument was discovered during the first period of the excavation activities of the American Archaeological School in Athens (1931).  The building’s foundations are composed of solid, finely worked pebbles.  The outer slabs of the euthenteria (measuring 9 Χ 5.5m.) were of Piraeus limestone, and were joined with metal Τ-shaped clamps, whereas the four steps of the base were of Pentelic marble. These steps survive at their full height in the north half of the west side, while only the two lower steps survive in the other sections of the altar.  Only one slab comprises two steps.  Their great weight was the reason why later ‘visitors’ to the site could not ransack the architectural members of the altar.  The dimensions of the base, at the height of the lower step, measure 8.76 Χ 5.4m. Obviously, the altar was situated in the east part, while the west part probably encompassed a colonnade through which the priest would approach the altar.

An orthostate was discovered east of the foundations. One of its ends is angled, while the other one is broken.  The height at which it survives is 2.90m. The stanchion bore intricate sculpted decoration with a guilloche at its base, Lesbian cyma and astragal, while fragments of a similar post were discovered in a well in the area earlier taken over by the propylon of the Metroon (Registry).  The architectural decorative elements confirm the dating of the altar to the 4th century BC.  The existence, however, of structural elements of the type encountered in the Temple of Ares, indicates that this monument was moved to the Agora at the same period as the ‘Temple of Ares’, together with other Attic monuments of the 5th and 4th centuries.

Its original location is unknown.  It is thought, however, that it could be identified with the monument whose footprint in the hill of Pnyx, immediately above the Rostrum (Bema), is of similar dimensions.  The repositioning of the monument possibly coincided with the relocation of the meeting-place of the Ecclesia from the hill of Pnyx to the Theatre of Dionysus.  If this suggestion is correct, then the altar was dedicated to the patron god of oratory, Zeus Agoraios, and should be dated to the period of the orator Lycurgus (approximately 340 BC).  According to the unnamed commentator of Aristophanes' Knights (comment on line 500), a statue of Zeus Agoraios stood in the Agora, as well as in the assembly point of the Ecclesia. 

BALDASSARI, P., ΣΕΒΑΣΤΩΙ ΣΩΤΗΡΩΙ. Edilizia Monumentale a Atene durante il Saeculum Augustum, Archaeologica 124, Roma, Giorgio Bretschneider Editore 1998, pp. ….
BURDEN, J.Ch., Athens Remade in the Age of Augustus: A Study of the Architects and Craftsmen at Work, Dissertation, University of California, Berkeley 1998, pp. ….
Mc CAMP II, J., The Athenian Agora: A Guide to the Excavation and Museum, 4th ed., Athens 1990, pp. 68-69.
Mc CAMP II, J., The Athenian Agora: Excavations in the Heart of the Classical City², Cambridge University Press 2001, p. 224. 
STILWELL, R., “Architectural Studies. VI. The Altar”, Hesperia 2 (1933), pp. 140-148
THOMPSON, H.A., “Activities in the Athenian Agora: 1951”, Hesperia 21 (1952), pp. 91-93.
THOMPSON, H.A., WYCHERLEY, R., The Agora of Athens. The American Excavations in the Athenian Agora, vol. XIV, American School of Classical Studies at Athens, Princeton 1972, pp. 160-162. 
TRAVLOS, J., Pictorial Dictionary of Ancient Athens, Princeton 1971, pp. ///. 
WYCHERLEY, R., The Agora of Athens. Literary and Epigraphic Testimonia, The American Excavations in the Athenian Agora, vol. III, American School of Classical Studies at Athens, Princeton 1957, pp. 122ff.