It is in Desert, about 52 steps north-east of the spot the map marks with that name.

And 1 down from the surface once you are there.

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

• Key 4022: a locked door bars the way, and that is the number of the key that opens it.
• Something for orc berserker, beholder and slime — they live down there.

The chest is 1 floor under the surface. Going down over it, this is what each floor uses:

1. Ground: down through a ladder.

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

• 1 — the chest
• 2-5 — Desert Dungeon Exit · tiles to step on
• 3 — a tile to step on
• 4 — a tile to step on
• 6 — a tile to step on
• 7 — Desert Dungeon Exit

The strongest 14 of 22 kinds whose nests reach this place.

One chest, one reward.