Abyss

The Abyss is the birthplace of Demons. In theory, it has an uncountable quantity of layers. Currently, it is controlled by the Tanar'ri. It is associated with Chaos and Evil.
See the external link for a much more detailed description of the Dungeon's and Dragons lore of the abyss - and how it is viewed and referred to in the Forgotten Realms campaign, to which this game is set in.
Note that The Abyss is an area reachable at the tail end of Baldur's Gate II: Shadows of Amn during Chapter 7.
==Game use of "Abyss"==
Although the game files refer to a map and area as The Abyss - the dialogue, journal entries and text refer to this area as "Hell" or the Nine Hells as several of the Tears of Bhaal tests fiends call it. The plot at this point is making it clear that the party is somewhere in the Nine Hells. 
In fact, there will be a player journal entry registered here titled Finding Irenicus in Hell.
The Bioware Game design isn't really following the lore on the differences between The Abyss and the Nine Hells at this point of the game. For instance, the player will interact with Demons, and not Devils, or maybe just refer to them as Fiend to get around this. The Abyss area map even has an Automap note feature titled "The Abyssal Door".
On older BG2 forums and various fan made mods or web pages, the Tears of Bhaal tests are often referred to as the Hell Trials - but that misnomer isn't ever used by the game. It's just a made-up fan title that lives on in the internet forums and various walkthroughs, and even some mods.
Only Greed (Abyss) actually gives a title for the various challenges faced by the bhaalspawn here, and it is referred to as a "test", and not a "trial".
== External links ==
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