Late attestations for an equation with the Black Sea abound, the cause being – as it appears – Odysseus' travel to the Cimmerians whose fatherland, lying beyond the Oceanus, is described as a country divested from sunlight. In the fourth century BC, Hecataeus of Abdera writes that the Oceanus of the Hyperboreans is neither the Arctic nor Western Ocean, but the sea located to the north of the ancient Greek world, namely the Black Sea, called "the most admirable of all seas" by Herodotus, labelled the "immense sea" by Pomponius Mela and by Dionysius Periegetes, and which is named "Mare majus" on medieval geographic maps. Apollonius of Rhodes, similarly, calls the lower Danube the "Kéras Okeanoío" ("Gulf" or "Horn of Oceanus").