Rab is a town on the island of Rab in Croatia. Rab, the settlement, is located on a small peninsula on the southwestern side of the island. …Rab is a town on the island of Rab in Croatia. Rab, the settlement, is located on a small peninsula on the southwestern side of the island. The town has a long history that dates back to 360 BC when it was inhabited by the Illyrians. The island was the frontier between the regions of Liburnia and Dalmatia. From the third century BC to the sixth century AD Rab was part of the Roman Empire, and Emperor Augustus proclaimed it a municipium in 10 BC. It was the first town of Roman Dalmatia to be given the honorary title "felix".