The ruins of the ancient port of Kenchreai lie 7 kilometres from Isthmia beside the main road south to Epidavros and Argolis.

Kenchreai served as Corinth’s main port on the Saronic Gulf throughout antiquity and continued to be a major port in Roman and early Christian times. The sea level has risen appreciably since those days and most of the site now lies beneath the waters of Kehries Bay.

Despite this, the layout is easy enough to discern. Engineers improved what was already a fine natural anchorage by building moles out into the bay to create a perfect horseshoe harbour. The site’s car park is right next to the southern mole, where the foundations of an early Christian basilica lie partly submerged on the shoreline. Beyond the basilica, now completely submerged, stood an ancient Temple of Isis. Exploration of the temple uncovered the exotic opus sectile glass mosaics now displayed in the museum at Isthmia.