Before killing one of his fighters Giorgio tells him "don't forget to pay the ferryman". In Greek mythology when a person died their soul would be sent to the shores of the River Styx in the underworld. In order to reach the other side and enter Hades (the afterlife) they have to be ferried across the river by Charon, the ferryman. But in order to do so they must pay the toll for crossing the river, if they didn't have any money to pay Charon they would not be able to cross the river and enter the afterlife and their soul would be cursed to wander in limbo for eternity. Hence the ancient Greek custom of placing two coins over the eyes of a person when they are buried, the coins are to be used to pay Charon's toll.
The Pillars of Hercules refer to the two promontories which border the Strait of Gibraltar. On the European side is the Rock of Gibraltar. The African side is in dispute, being a mountain in either Algeria or Morocco.