Stonehell Dungeon: Down Night-Haunted Halls (2009)

From the rear cover:

Beware All Who Enter
These Benighted Halls of Stone.
Within Lies No Solace
Nor Any Comforts of Home.
Toiling For Our Crimes
We Must Dig Where We Dwell,
With No Freedom or Mercy
In Our Vast Stony Hell.

-Inscription over the entrance of Stonehell Dungeon

Stonehell Dungeon is a classic-style megadungeon, filled with enough monsters, traps, weirdness, and treasure to keep you gaming for a long, long time. Explore over 700 rooms, encounter more than 40 new monsters, and discover 18 mysterious magical items -- and that's just in the first book!

Stonehell Dungeon: Down Night-Haunted Halls details the first six levels of a megadungeon intended for use with the Labyrinth Lord™ role-playing game, but is easily adaptable to most early versions of the original fantasy role-playing game and its retro-clones. Stonehell Dungeon gives the game master all the necessary information to run his players through the dungeon, while offering enormous opportunities to customize and expand on the site.

The monsters of Stonehell Dungeon are waiting to meet you. Won't you come in?