In my current novel, there is a door which, they say, leads to the land of the dead. If you look here, you’ll get an idea of just how popular this idea was in mythology all over the world. It seems that every world mythology had some form of the land of the dead. Possibly the most well-known is the greek Hades where the dead paid a coin to the ferryman, Charon, to take them across the river Styx (or Acheron). Those who did not have the coin couldn’t enter the land of the dead and returned to haunt the living.
Many stories involve the souls of the dead being judged according their actions before or just after entering the land of the dead to determine their afterlife destination. In some mythologies, it was the souls of warriors who died in battle who went to paradise. In Egyptian mythology among others, the fate of the dead was decided by a series of fearsome tests. Others had more bizzare ways of determining the fate of the dead: In Aztec mythology, it was those who died in water or by lightning in a rainstorm (or other water-associated death) who were taken to the endless springtime of Tlalocan. The Hebrew Sheol is simply a mass grave where the dead lie dormant, though some say they await the resurrection and the day of judgement.
One literature teacher I had said one that by far the two most popular subjects for poetry and fiction are love and death. The myriads of stories of the afterlife and of ghosts and other undead monsters in folklore and modern fiction show that the mystery of death (and what comes after) is possibly the most limitless invitation to the imagination to create stories and speculation. It’s a subject that doesn’t easily get tired out. So of course I’m taking advantage of it.