The Deep is an especially deep network of caverns on Luclin, which is rumored to be very deadly.
There is a deep Abyss, a pit of unfathomable depth, deep within this network of caverns. There is a large bridge that passes over this, however the bridge is an illusion, and stepping on it will lead to a very nasty (and likely lethal) fall to the bottom of the Abyss.
Travelling To and From The Deep
The entrance to the Deep is through the southern section in Echo Caverns.
The Deep connects to Ssraeshza Temple through a passage deep within it. Although the passage itself is not one way, shortly into the Temple you will pass through a one-way door and not be able to go back to the Deep.
Nostalgia from 1999-2003 EQ Atlas Web Site