As for life after death, the Greeks believed that the abode of the dead was the Kingdom of Hades, the god of the underworld, alongside Persephone (Goddess of spring, daughter of Zeus and Demeter). Hades was Zeus's brother. It was located underground, surrounded by rivers, which can only be crossed by the dead. The dead preserved their human form, but had no body, could not be touched. The dead roamed Hades, but they also appeared at the burial site.
There were careful rituals at burials, and the dead were worshiped, mainly by families in their homes. When the men died, they were transported, on the Charon barge, to the other side of the Aqueron river, where it was located at the entrance to the kingdom of Hades. The access was through a diamond door next to which Cerberus stood guard. To calm Cerberus' fury, the dead who lived in the underworld threw him a cake of flour and honey that his internal loved ones included in the tomb.
His name, Cerberus, comes from the word Kroboros, which means meat eater. Cerberus ate people. An example of this in mythology is Pirítoo, who for trying to seduce Persephone, was given to the dog. As a punishment Cerberus ate the body of the condemned. Cerberus, when he went to sleep, has his eyes open, however, when he has his eyes closed, he is awake.