@x trench run: Based on the description, this is almost certainly a standalone adventure from Dungeon Magazine during the D&D 3.0/3.5 era, exploiting the motif of going deep underground through a pit or vertical shaft, with multiple levels and dungeons interspersed at different depths, and not part of the Shackled City Adventure Path. However, with only the available details, it's impossible to pinpoint the exact name and issue number, as this motif appears in many different issues during that period. The most effective way to find the correct adventure is to cross-reference Dungeon Magazine. Index (issues 82–154) and narrow down the scope by adding further details such as character levels, signature monsters, or specific settings.
