Gerrhos
Gerrhos (Greek "reed-swamp") is a place in Scythia essential to interpreting Herodotus' world-map, for it formed one of the corners of the great square that defined Scythia. A more familiar Gerrhos or reed-swamp — from the Alexandrian point-of-view — lay to the east of the mouth of the Nile. Herodotus drew a meridian between the two Gerrhoi: that in Scythia was considered the source of the Boristhenes Dnieper. In the words of Herodotus (IV.53):
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