The designation of a type of geocache used in the GPS game of geocaching that contains an unknown element that needs to be figured-out before the location of the cache becomes knowable. Examples of mystery elements that a mystery cache could contain include: games to play , field puzzles using information found at the listed coordinates, information hidden within the cache page or content, passwords, ciphers or codes and many more possible unknowns.
Holy crap, it took me a week to discover that the password to that mystery cache was shamalamamoomoo!
by swagzombie June 15, 2016