** Bodies had lain in beehive-shape tombs on this necropolis, part of the prehistoric hill fort of Drviica, since the Iron Age. The two dogs, trained to detect human remains, were searching for scents that were thousands of years old. **
Which is it? Prehistoric or Iron Age? I understant that the fort could go back much further but attaching that adjective fuzzes up the whole description.
The Iron Age began around 1200 B.C. in some areas (iron-working wasn't introduced at the same time everywhere). 8th century B.C. is when the Greeks began to colonize new areas including Corcyra (Corfu) and Syracuse; there were a few Greek colonies in the Adriatic but the earliest ones there seem later than the 8th century. There were Greek colonies on the islands of Corcyra Melaena (Korcula), Issa (Vis), and Pharos (Hvar), and at Tragourion (Trogir) on the mainland. We don't have any writings from the native population of this area (Illyrians) so it can be considered "prehistoric."
Drvisica is near Karlobag, on the Croatian coast opposite the island of Pag in the northern Adriatic.