Buried Sanctum

 is a treasure room located to the west of Jailbreak Tunnel. When entering, all parties are disbanded. It can be accessed by collecting all four Rusty Keys from the minibosses of Jailbreak Tunnel. Two Deluxe Boxes can be found sparkling at the end. 

NPCs
Lt. Magneton can be found sleeping near to these treasure boxes. He only says one thing.


 * Lt. Magneton: BZZZ... ZZZT... ZZZZT...BzzZT...!

Deluxe Box items

 * Courage Dust
 * Revive
 * Big Nugget
 * Nugget
 * TM Shadow Claw
 * TM Thief
 * Heart Scale