Dark Miners' Treasure Map

 is a Quest Item.

Obtaining

 * Dropped by
 * Dark Miner

Uses

 * Go to Porco Territory at [0,33] and stand behind the house to enter the secret cave.
 * After entering, you may encounter a Dark Miner in very close combat, so be prepared for a fight.
 * After passing through the tunnel, you'll be at [1,34] with the Malicious Chest.