According to myths, either the Corinth was built by Corinthos a descendant of god Helios-Sun or by Ephyra, a daughter of the Titan Oceanus. The today's appearance of Corinthos has been formed at 1858 after a major earthquake. At the modern town of Corinth, one can see the archaeological museum, the temple of Apollo build during pre-Roman period, the ancient Agora and few Roman buildings. Do not forget to see Apostle’s Paul metropolitan church with the fabulous mosaic. A True fact: At Corinth, Apostle Paul met Akyla and Priscilla. That couple are the Greece’s “Valentine Saints”.
Continuing the tour, 48klm south of Corinth one can visit meet king’s Agamemnon town Mycenae (World Heritage of Unesco). Τhe Lion Gate, the Cyclopean Walls, the Tomb of Agamemnon (called also Treasury of Atreus from 14th century B.C.) and Tomb of Clytemnestra are some of the sight seeings that the visitor can see at the place. Mycenae was the capital of the ancient Mycenaean Civilization, which bloomed between 1600-1100 BC. Someone can also see the Royal Palace and the Mycenean Archaeological Museum.
A little bit further is the city of Nafplio with its Venetian fortress of Palamidi and the church where the first Governor of Greece (Ioannis Kapodistrias) was murdered. 
Nafplio was the first capital city of modern Greece. The Venetians used to call it the Naples of Greece. You can easily see the Venetian fortress of Palamidi on the top of a hill above and the fortified islet of Bourtzi in the old port. The old town was built at the beginning of the 19th century but many buildings still exist from the Venetian time. During the tour, one will visit the Cathedral and the church of Saint Spiridon where Ioannis Kapodistrias was murdered. Like Athens, Nafplio has also a Syntagma Square. In the old city the visitor can explore its historic buildings from different periods such as the building of Archaeological Museum, the Vouleftikon that hosted the first parliament of the free Greek state and the Old Mosque.
The tour can be ended at Epidaurus (World Heritage by Unesco) where Apollo’s son Asklepios was healing people close to the theater. This Ancient Theater, build in 4th century BC, is still in use every summer with lots of theatrical, mostly dramatic, performances. Its capacity is up to 14.000 people and has a really exceptional acoustic.