Areopagus

the Latin form of the Greek word rendered "Mars' hill." But it denotes also the council or court of justice which met in the open air on the hill. It was a rocky height to the west of the Acropolis at Athens, on the south-east summit of which the council was held which was constituted by Solon, and consisted of nine archons or chief magistrates who were then in office, and the ex-archons of blameless life.

On this hill of Mars (Gr. Ares) Paul delivered his memorable address to the "men of Athens" (Acts 1:17-31).

EBD - Easton's Bible Dictionary