The excellent Museum, which is recommended for the first stop, stands at the top of a rise by the road. Open Tues-Sun; 8:30am-3pm; free—same hours as site.
The modern town lies on either side of the Saronic Gulf entrance to the Canal. The ancient site is to the south, on a hill beside the modern village of Kyranos (or Krias) Vrysi.
The Sanctuary of Poseidon is on a natural terrace between the village and the Isthmian Wall which extends for 9.5km across the narrowest part of the isthmus through which the Corinth Canal was cut. Considerable traces of the wall fortifications remain, following a natural line of low cliffs, and can be traced for its entire length, the best preserved part being that just east of the Sanctuary, where the wall is 7meters high and 2.5meters thick.
The Sanctuary of Poseidon was one of the four Panhellenic sanctuaries mentioned and praised in the Odes of Pindar, which was famous for its games (the others being Olympia, Nemea, and Delphi). As with these others, the games at Isthmia are believed to have originally honoured the funeral of a particular hero.
Legend has it that Melikertes (the Phoenician Melkarth), who leapt into the sea with his mother from the Molurian Rock, was taken to the isthmus by a dolphin. Corinth at that time was enduring a famine, and an oracle instructed that only a proper burial and games to honor the drowned boy would end the famine. The games that followed from this were given the boy's name, which was (for some reason) changed to Palaimon. Afterward the oracle further instructed that the games continue in perpetuity to prevent the return of famine.