In the site that the harbour of Hersonissos is built today, there was the city of ancient Hersonissos. The Roman Hersonissos had wonderful marble waterfalls. The city was first built during the Minoan times but experienced great prosperity during Roman and early Byzantine period.
Remnants of this period can be seen today in the area of Kastri, on a promontory where excavations have revealed an early Christian basilica.
The ancient city of Hersonissos was irrigated by an aqueduct, ruins of which can be found today at Xerokamares, at the village of Potamies.