This is a bonus cache for the Dying to Meet You in Altadena Adventure Lab.
The cache is not at the posted coordinates. The posted coordinates take you to a good parking spot for both the Adventure Lab and the final cache. The actual cache location is N 34° 11.2AB W 118° 09.CDE where the missing digits can be found by completing the Adventure Lab.
UPDATE 3/3/21: Because of a recurring muggle problem at the original location, I have moved the cache to a new spot -- still an easy stroll from the posted coordinates. The coordinates have changed (obviously), so the journal entries in the Adventure Lab have also been updated. If you retrieved information before March 3, it's now obsolete. Review the journal entries again to get the new coordinates.