The ancient city stood on the site of today's small town and was very prosperous in the Greco-Roman and Early Byzantine periods; it was fortified under the Venetians and thus acquired its modern name of Kastelli (castle). The Classical and Hellenistic town was on Seli hill. Kasteli is situated in the bight of the bay and is the seat of the bishopric of Kisamos and Selinos. The heyday of Kisamos was in the Roman period. The most important building uncovered in recent excavations by S. Markoulaki is a large house dating to 250-300 AD with fourteen rooms and an inner paved court. Fine polychrome mosaics were found in two of the rooms depicting subjects from nature and mythology. Mosaic floors have also come from houses excavated in other parts of the town, depicting a variety of subjects, including a couple embracing, a boy picking grapes, women dancing, and so on. Other excavations have brought to light fine statues, relieves, coins, figurines, fresco fragments and architectural members from large public buildings like baths, a theatre and Kastelli has a small museum with a few finds from ancient Kisamos. Wine and olive oil are the major products of this area. The ruins of the ancient city of Polyrrinia founded by the Achaeans and Dorians lie seven kms inland from Kastelli, on a hill above the village of Polyrrinia. The city was was continuously inhabited until Venetian times. There are remains of city walls roads and houses, and an aqueduct built by Hadrian. It's a scenic walk from Kastelli to Polyrrinia, otherwise there is a very frequent bus services.