The exact location of Idunum is unknown, but it is most likely that this Celtic settlement from the Hallstatt period was either in the valley of the Drava or the Gail . Remnants of the wall were found on the Gurina in the Dellach community in the Gailtal , which have been preserved at a height of up to 2.40 m; later the Romans also built a fortified base at this point. Other evidence suggests a location near Irschen on the Drau.
- Peter Jablonka : The Gurina near Dellach in the Gailtal. Settlement, trading center and sanctuary . 2001, ISBN 3774929718