Pella is a favourite of archaeologists as it is exceptionally rich in antiquities, some of which are exceedingly old. Besides the excavated ruins from the Graeco-Roman period, including an Odeon (theatre), Pella offers visitors the opportunity to see the remains of a Chalcolithic settlement from the 4th millennium BC, the remains of Bronze and Iron Age walled cities, Byzantine churches and houses, an Early Islamic residential quarter, and a small medieval mosque.