[IC] Chapter 1-4: Cellars of Hate

[DM Surranó]

The cellar is rectangular, or even square, roughly 100 by 100 feet with a roughly 40x50 feet block of wall in the middle, featuring a door.
Imagine it as the double of the "ground" floor without the walls between rooms and with the completely blocked inner yard (spoiler: call it "garden") being the closed-up area in the middle -- except that the whole space is smaller than the ground floor and the middle part is smaller than the garden. From Lugar's dwarven legacy it's not impossible that this confinement is actually a basement (or at least foundation) of a small building that is in the garden.

Everything including the iron door stands in water so murky that you cannot penetrate it by sight, not even darkvision, for more than a few feet. You notice diminutive colorless creatures scurry and swim out of the area your light source affects.
There seems to be a slope or some stair steps in front of the door since it's almost completely below water level, making it a hard target for prying or knocking down.

The air, though stale, is surprisingly easy to breath for such a place.

There seems to be nothing of value left.

EDIT: revised my notes. Added some detail on the water and the iron door, above.