It is in Sternum, about 68 steps south-east of the spot the map marks with that name.

And 8 down from the surface once you are there.

• 1 — Sternum, as the map itself names it
• 2 — the ground above the treasure

• A rope. You drop in through a hole and a trapdoor, and a rope is how you climb back out.
• Something for demon, giant spider and dragon — they live down there.

The chest is 8 floors under the surface. Going down over it, this is what each floor uses:

1. Ground: down through a ladder.
2. 1 down: down through a hole.
3. 5 down: down through a trapdoor.
4. 6 down: down through a hole.
5. 7 down: down through a hole.

• 1 — the way in: a ladder, ground
• → — the treasure lies this way

• 2 — a hole, 1 down
• → — the treasure lies this way

• 3 — a trapdoor, 5 down
• → — the treasure lies this way

• 4 — a hole, 6 down
• → — the treasure lies this way

• 5 — a hole, 7 down
• → — the treasure lies this way

Some floors are not on the list: their way down is further off than the rest, and that stretch you have to find yourself.

• 1 — the chest

The strongest 14 of 19 kinds whose nests reach this place.

One chest, one reward.