The party finds a small box that will only open in one specific location in your campaign world. When the party tries to open it anywhere else, a ghostly face appears over the lid and tells the party that the chest may only be opened in a location x leagues, miles or feet away. It will then say a number before it disappears, which starts at 20 and counts down each time they attempt to open it.
The players may attempt to open the chest only 20 times. On the 21st attempt, it will teleport back to where it was found (50% chance) or to the spot where it can be opened (50% chance). Attempting to open it with a wish spell will have the same effect. Lesser spells have no effect.
This was inspired by a real product, that uses a GPS-based lock that will only open in one location on earth. Be sure to read the article to see how the recipient managed to solve the puzzle. It shouldn’t take anywhere near 20 tries, unless you place the special spot underground.