Chekov's Spell -- This spell has a two-fold effect. The first is to make the target item almost-unnoticeable to anyone not specifically looking for it. The second is that someone who has seen the item will remember it when they encounter a situation that would be perfectly solved by use of said item.
A typical iron ore mine, the Irongate was closed some years ago and the entrance was closed off with a heavy gate of oak and thick iron bands, the Irongate. The mine itself was abandoned because it was a breeding ground for dire rats and many of the miners suffered from giant rodent bites as well as diseases from said bites. The mines are haunted by the ghosts of the men who died in dire rat swarms, adding to the mine's unpleasant character.