The Abyss is the deepest, darkest part of any water mass. Many strange and deadly creatures lurk at the bottom. It is accessed by a trench in Wicked Thicket. It goes down about 25 Miles until it reaches the water.
Around 5,000 miles
26,400,000 Feet ( I think )
The Abyss is said to be where the remains of Atlantis sit.