A periplus in the ancient navigation of Phoenicians, Greeks, and Romans is a manuscript document that lists in order the ports and coastal landmarks, with approximate distances between, that the captain of a vessel could expect to find along a shore. Several examples of a periplus have survived.
The Periplus of the Erythraean Sea (q.v.) was written by a Romanized Alexandrian in the 2nd century CE. It gives the shoreline itinerary of the Red (Erythraean) Sea, starting each time at the port of Berenice. Beyond the Red Sea, the manuscript describes the coast of India as far as the Ganges River and the east coast of Africa (called Azania).