With the official timeline advanced to mid-1372 DR in the FRCS3, there are two options a DM has when deciding the current state of the Haunted Halls:
The former requires significantly less preparation, while the latter requires the DM to exercise his or her own creativity. Personally I have chosen option two, and how much is posted here depends on the amount of free time I have and whether or not WotC decides to release a new Haunted Halls adventure.
From a sidebar in the FRCS3 we learn of the Mages-Regal, who created the portals in the lower levels of the Halls. See the FRCS3 for a little more information on these mages, and I suspect that we will see more official details later.
Location: Shown in the FRCS1, FRCS2, VGtC, and the FRIA - about 8 miles north of Eveningstar.
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Though the Haunted Halls are the prime location for adventure in the Eveningstar area, I have also listed other locales with some minor notes concerning what may potentially be found there as drawn from FRQ1 and the FRCS3.
Very little detail about this cavern complex has been published other than the fact that it is continually restocked with the trolls that are its namesake. FRQ1 suggests that this may be the result of a deepspawn infestation or a conscious effort by Zhent forces. Nothing more is added in the FRCS3.
Location: Not shown anywhere. I suggest a location about 10 miles east of Eveningstar in the Stonecliffs.
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All existing details regarding this location are found in FRQ1. Infested with shadows, it could hide a greater foe as well, or may simply be a Zhentarim trap.
Location: Not shown anywhere. Any location not too far away in the Stonelands is suitable.
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Minimal details about Hidden House may be found in the FRCS3. From the novel Crown of Fire, we know that Tessaril is charged with protecting this secret extra-dimensional hold as a Crown resource.
Location: Accessible through a portal in Tessaril's Tower.
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Minimal details about Irongard may be found in FRQ1, while Dungeon Magazine #18 contains an excellent short adventure for this locale by Ed Greenwood. Though Irongard is mentioned in FRQ1 as a source of additional adventure while in Eveningstar, please make note of the location shown in the FRIA. Nothing more is added in the FRCS3, though it is now referred to as "Ironguard" in that source.
Location: Shown in the FRIA - about 32 miles northwest of Arabel.
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Some details regarding this abandoned keep were given in FRQ1. A Zhentilar force under the leadership of then-mortal Cyric explored the ruins during the Time of Troubles [1]. Knowing the attitude of the Zhentilar, any traps sprung or found by other means were reset and more traps added to the keep as a whole for later explorers to "enjoy." Overall the ruins will have changed very little due to the short occupation, but for consistency a DM should add details to show that the Zhentilar were there, i.e. unused firewood, anti-Cormyrean graffiti, etc.
Location: Shown in the FRIA - about 7 miles north of the Haunted Halls.
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[1] Waterdeep, Book Three of the Avatar Trilogy of novels by Richard Awlinson. Note that the author mistakenly states that the keep was built before Cormyr became a kingdom. Rivior's Keep was built not too long before the Haunted Halls were completed circa 1147 DR, and Cormyr had long since become a kingdom by then.
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FRQ1 says that his burial mound may contain undead creatures of great martial prowess serving a sorcerous lord, the latter of which may be a nabassu tanar'ri. This has changed in the FRCS3, which states that the crypt is in use by the Zhentarim and that it is guarded by their own creatures.
Location: Not shown anywhere. Any location not too far away in the Stonelands is suitable.
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Minimal details about this hidden complex may be found in the FRCS3 and it is rumored that minor magical treasures may still be found there.
Location: Attached to the Haunted Halls via a long tunnel in the lower levels.
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