Beyond lay Erebus, which could be taken for a euphonym of Hades, whose own name was dread. There were two pools, that of Lethe, where the common souls flocked to erase all memory, and the pool of Mnemosyne ("memory"), where the initiates of the Mysteries drank instead.
From Wikipedia, 4/30/2018
The Mysteries refers to a cult of Demeter.
The pool of Mnemosyne is not often mentioned and I can't find much else on it.
Can information about it be expanded upon?
An early mention of the pool of Mnemosyne can be found in the Petelia Gold Tablet, an Orphic inscription from between 300-200 BC:
You will find in the halls of Hades a spring on the left,
and standing by it, a glowing white cypress tree;
Do not approach this spring at all.
You will find another, from the lake of Memory
refreshing water flowing forth. But guardians are nearby.
Say: “I am the child of Earth and starry Heaven;
But my race is heavenly; and this you know yourselves.
I am parched with thirst and I perish; but give me quickly
refreshing water flowing forth from the lake of Memory.”
And then they will give you to drink from the divine spring,
And then you will celebrate? [rites? with the other] heroes.
This [is the ? … of Memory, when you are about] to die ..Wikipedia contributors. (2018, March 20). Petelia Gold Tablet. In Wikipedia, The Free Encyclopedia. Retrieved 19:57, May 23, 2019, from https://en.wikipedia.org/w/index.php?title=Petelia_Gold_Tablet&oldid=831347660
