Riduna
Riduna one of the islands off that part of the Gallic coast which was occupied by the Armoric states. As the Marit. Itin. mentions Caesarea (Jersey), Sarnia (Guernsey), and Riduna, it is concluded that Riduna is Aurigny or Alderney off Cap de la Hague.
From William Smith (ed.), Dictionary of Greek and Roman Geography. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.