Rabba is an unassuming village 10 km north of Karak on the King's Highway, but its main street runs straight past the ruins of a small Roman temple. Two tall columns and part of an entablature still stand, with inscriptions referring to the emperors Diocletian and Maximian. In Roman times the town was called Areopolis and served as a way-station between the Decapolis and the Red Sea.
There is no entrance fee, no signage to speak of, and no facilities — but if you are driving down the King's Highway it is well worth pulling over for fifteen minutes. The villagers are used to passing tourists and tend to be friendly.