The port of Patras has ferry links to Venice, Ancona, Bari and Brindisi in Italy, Igoumenitsa in northern Greece and Corfu. It’s a sprawling modern city that is difficult to navigate around; unless you are getting a ferry there is no reason for tourists to visit. There is a new bypass that circles the back of the city up in the hills.
North of Patras is the Rio-Antiro suspension bridge that links the Peloponnese to mainland Greece. This is a good route to take to visit Delphi and the bridge is stunning.