A really nice puzzle that requires some good map reading... [:)]

1+2+cache in Bochums Süden

This cache is a great mystery to many geocachers [;)].

Basic Instinct

Enigma is the mother of all geo-mystery caches. No, not so much the more history-related ten initial puzzles or the encrypted texts on the maps but the really creative maps themselves that need to be de-coded! [^] 

Enigma #1

Needs some map reading, some poetry interpretation and some basic knowledge about the behavior of ducks... [;)] It also features a very well-done final location! [^]

Erpel

This cache not only features a nice art puzzle but also requires some map work. A special map? Yes! The "I'm a serious geocacher"-map, of course... [;)][:)]

Finde mich, wenn du kannst 2 - Verzauberter Wald

Well, we haven't exactly completed this one yet. But it is already clear that it is a well done geo-mystery... [^]

Finde mich, wenn du kannst 3 - Kauderwelsch?

This is about the classical art of celestial navigation... 

Master of Navigation

This interesting cache not only requires to solve an important geodesy/navigation task (i.e. obtain exact coordinates from two horizontal angle measurements) mathematically - but it also has a nice final location!

Master of Trigonometry

Time is *the* essential ingredient to determine exact longitude coordinates. That is a fact that took its time (i.e. centuries!) to be realized by science. Nice cache that involves some research into the concept of time as it is requred for navigation/geodesy.

Ortszeit in Bochum

The godfather of a number of caches that make use of this "encrypted" way of locating a spot.

Stationszeichen

This is our completely uncomplete list of great geo-mystery caches (i.e. in our absolutely personal opinion) - picking only from those we found so far [^]. 

Geo-mysteries? Yes, this list is about mysteries that have a direct relation to geo-sciences like geodesy, to navigation, coordinates, geocaching as such etc. This list does not imply that we don't like other mysteries. In fact, code and encryption caches, or funny/creative math puzzles, for example, are also fun - but just not included in this list. [:D]

<b>Warning:</b> Some of the remarks below can be considered spoilers. 

HoPri's list of nice Geo-Mysteries.list-details-1wr9x6v{text-transform:uppercase;font-size:12px;}@media screen and (min-width: 600px){.list-details-1wr9x6v{font-size:1.25rem;}}.list-details-1wr9x6v.shareable{color:#87705a;}.list-details-1wr9x6v.public{color:#00b265;}Public

HoPri's list of nice Geo-MysteriesPublic