The district of Ialysos encompasses the northern part of the island. It was inhabited in the prehistoric period. Remains of a Minoan settlement have been found at Trianda and Mycenaean cemeteries have been located on the surrounding hills of Makria Vounara and Moschou Vounara (1700-1400 BC).

The ancient city of Ialysos extended around the hill of Philerimos, which was the ancient acropolis where there are remains of buildings from the Archaic, Byzantine and Knights' periods. The temple of Athena Polias, which dates to the 3rd-2nd c. BC, was built over the site of an earlier Classical temple, to judge from from the evidence of a 5th c. BC floor and terra-cotta antefixes found there. The depository on the west side produced pottery and votive offerings dating from the 9th to the 5th c. BC. In addition to the cult of Athena Polias, there are also references to a cult of Zeus Polias. In the Early Christian period (5th-6th c. AD) a three-aisled basilica with an atrium was built on the remains of the ancient temple, in the north aisle of which a single-aisled church with a cupola was constructed in the 10th c. In the time of the Franks this site was occupied by a medieval monastery and church.