It's the bonus cache of the cryptomaniac series. You have to find (nearly) all other caches of this series to be able to "unlock" the coordinates.
Cryptomaniac #1
Cryptomaniac #2 Bonusletter: F
Cryptomaniac #3 Bonusletter: N
Cryptomaniac #4
Cryptomaniac #5
Cryptomaniac Bonus
This series has some really hard riddles, one boring city micro/tradi, one with a really hard terrain rating, overall you have to be very versatile to find all the caches of the series.
You have to find nearly all the other caches of the series, they have letters on first page of their logbook, which are needed to unlock the coordinates. The coordinates are locked inside Cryptomaniac #5, you'll find a detailed description in the encrypted text of this cache.
The header coordinates are pointing to a parking area.
The cache contains three times the book "Geheime Botschaften" of Simon Singh, it's a bonus for the first three finders.