Pomponius (c. 43 AD) is unique among ancient geographers in that, after dividing the Earth into five zones, of which two only were habitable, he asserts the existence of antichthones, inhabiting the southern temperate zone inaccessible to the folk of the northern temperate regions from the unbearable heat of the intervening torrid belt. On the divisions and boundaries of Europe, Asia and Africa, he repeats Eratosthenes; like all classical geographers from Alexander the Great (except Ptolemy) he regards the Caspian Sea as an inlet of the Northern Ocean, corresponding to the Persian and Arabian gulfs on the south.
His Indian conceptions are inferior to those of some earlier Greek writers; he follows Eratosthenes in supposing that country occupied the south-eastern angle of Asia, whence the coast trended northwards to Scythia, and then swept round westward to the Caspian Sea. As usual, he places the Rhipaean Mountains and the Hyperboreans near the Scythian Ocean. In western Europe his knowledge (as was natural in a Spanish subject of Imperial Rome) was somewhat in advance of the Greek geographers. He defines the western coast-line of Spain and Gaul and its indentation by the Bay of Biscay more accurately than Eratosthenes or Strabo, his ideas of the British Isles and their position are also clearer than his predecessors. He is the first to name the Orcades (Orkney Islands), which he defines and locates pretty correctly. Of northern Europe his knowledge was imperfect, but he speaks of a great bay (“Codanus sinus”) to the north of Germany, among whose many islands was one, “Codanovia”, of pre-eminent size; this name reappears in Pliny the Elder’s work as Scatinavia.