Of four infernal rivers that disgorge/ Into the burning Lake their baleful streams;/Abhorred Styx the flood of deadly hate,/Sad Acheron of sorrow, black and deep;/Cocytus, nam'd of lamentation loud/ Heard on the rueful stream; fierce Phlegethon/ Whose waves of torrent fire inflame with rage./ Far off from these a slow and silent stream,/ Lethe the River of Oblivion rolls/ Her wat'ry Labyrinth whereof who drinks,/ Forthwith his former state and being forgets,/ Forgets both joy and grief, pleasure and pain.
John Milton