Personna Park is a nice spot tucked away in the affluent Cachet neighborhood that, in my opinion, is not enjoyed as much as it should be. There are plenty of great hiding spots for geocaches here. I've opted to utilize one of the more difficult ones for this geocache.
The coordinates on this one may not be perfect--but you'll know that you're at GZ when you find yourself along the path crossing a small stream. The intersection between the path and the stream is GZ (in particular, I'd recommend starting your search on the side of the stream closer to the nearby houses and farther from the park itself). If you take note of the attributes on this cache, you should be able to narrow down the list of possible hiding spots. You may even spot the cache. But the only way to be successful is to reach the cache and sign the log inside.
This one is meant to be difficult, and you know your limits better than I do. If you do not feel safe during retrieval, please do not push yourself. I anticipate that this cache will be more difficult to retrieve during Winter--again, please assess your abilities accordingly. I would not encourage you to try finding this one at night unless you're really up for a challenge.
This cache is a small bison tube that may be hard to spot and harder to retrieve. The cache holds only a log, so please BYOP! :)
Congratulations to eccentric_elephants for FTF!
Update (09/13/2020): I decided to increase the terrain rating from a 4.0 to a 4.5--it's a difficult one, but I'm hesitant to give it a 5.0 because a) there is no need for special equipment, b) there is no hike required to access GZ, and c) I believe that the 5.0 should be reserved for truly exceptional caches, such as the one on the summit of Mount Everest. :)