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Altar of the Twelve Gods Near the middle of the open square, somewhat to the north, lay the Altar of the Twelve Gods (Fig. 7), today largely hidden under the Athens–Piraeus railway (1891). A corner of ... Herodotos (2.7), when giving a distance in Egypt, tells us that it is as far from Heliopolis to the sea as it is from the Altar of the Twelve Gods in Athens to Olympia.