It is dedicated to a King Nicomedes, most likely Nicomedes IV of Bithynia, which would place its composition around 90 BC. A geographical summary in iambic verse, it has some worthwhile material on the coasts of Spain, Liguria, the Euxine (Black Sea), data on various Greek colonies, as well as information about the ancient Umbrians, Celts, Liburnians, and other peoples.