Joani found this really evil hiding spot in a park that she played in as a kid. The cache is small and there are many possible spots. The difficulty is high because there are no hints provided. However, she says she is willing to provide a hint if you go to these coordinates:
N37 33.653
W122 19.260
and take a picture of you (or anyone, especially little kids) kissing the brass dog similar to the picture to the right (which is Joani's cousin, taken a long time ago). Log a DNF and upload the picture and you will get a detailed hint. 
The cache is a sign only micro that contains a log sheet. Bring your own pen (and a camera, if you think you might need the hint 
). Please take care to remove the cache carefully and replace it the way you found it so as not to spoil it for other finders.
About the dog:
The dog was made in Italy and was part of the Kohl estate that the city bought and turned into this park. It is one of the few items that remain from the original estate. There are plaques nearby with other interesting information. Nowhere does it mention kissing the dog though.
A note to out of town cachers:
If you want to get the hint in advance, you can if you agree to post a picture of someone kissing the dog when you log your find. This way you won't have to take two trips, which would be inconvenient if you are from out of town.