We (that's me and the Holy spirit) have been working towards the construction of a model of the interior of the Earth which fully integrates every possible way that hell or the afterlife is referred to in the Bible.
The Sides of the Pit
Graves and Pits
One of the repercussions of the fall of man was the start of nuclear decay. This in turn is the beginning of hell, since the explosive rate of decay, concentrated in the core of the Earth, caused the core to melt.
March 20th
If you're on a downward course and leave the lower mantle, once you enter the great gulf, there's nothing to stop your fall into the core. This means that the pit refers to everything below the mantle.