This is a very big celebration for the city of Patras in Peloponnese. Saint Andreas is the patron saint of the city and this is his name day, so this celebration is one of the biggest religious celebrations of Patras.
A custom related to a very old local legend, regarding a ghost protecting a local fountain, Charmaina. The legend said that there were more ghosts protecting other places and they would fight amongst them many times. The locals would hear the screams and hide in their homes. A quite spectacular event which gets very crowded.