Very large even in its earlier phases, occupied always the same position. Seven successive phases have been distinguished, of which the earliest, a small structure built of rubble, dates from the Late Bronze Age. The altar of the 8th/7th century B.C., for unknown reasons (possibly connected with the cult) was not placed on axis to the temple, but was orientated NW / SE. It acquired its monumental form in ca. 560 B.C., and was almost contemporary with the monumental temple of Rhoikos and Theodoros, placed on its axis. On the basis of the preserved foundations, its size is estimated to 36.50 X 16.50m. The temple opened to the main sacrifical area which was surrounded on three sides by a wall, 5-7m. high. This was decorated with impressive cymatia, and, on the interior, with a frieze showing fighting animals and sphinxes.The free edges of the two walls bear richly decorated anta capitals.In imperial Roman times (1st-2nd centuries A.D.) the altar was rebuilt of marble, and decorated with copies of the Archaic architectural decoration.