6.18 Beyond are the Sogdiani and the town of Panda, and on the farthest confines of their territory Alexandria, founded by Alexander the Great. At this place there are altars set up by Hercules and Father Liber, and also by Cyrus and Samiramis and by Alexander, all of whom found their limit in this region of the world, where they were shut in by the river Syr Darya, which the Scythians call the Silis and which Alexander and his soldiers supposed to be the Don. But this river was crossed by Demodamas, the general of King Seleucus and King Antiochus, whom we are chiefly following in this part of our narrative; and he set up altars to Apollo Didymaeus. Text used: Pliny. Natural History. Translated by H. Rackham. Loeb Classical Library 330. Cambridge, MA: Harvard University Press, 1938.