The missing piece

The The Missing Piece geocache (GCAC98) is a mystery rated 5 for difficulty, placed by mlord in Quebec in November 2002. It is the first mystery in Quebec, now archived.

The puzzle was a legal chess position — that is, one that could occur in a real game — with one piece missing. The white king was shown: it sat atop the flagpole of a place the listing designated by a pun, “Canada's three-time King”. The black bishop stood 2.2189 kilometres away, on a bearing of 274.97 degrees, and the owner pointed out there was no need to pay her a visit: as you can see, she is very busy. The treasure, of course, was with the missing piece.

The original container had been stocked with items of higher than average value, in proportion to the difficulty.

Fun fact: the creator of geocoins.io long believed this was the first mystery in the world, because of a bad reference found on the internet. It earned him a fair amount of teasing!