The cache is not at the posted coords, but they grow flowers there.
This is an Adventure Lab bonus cache. To determine the location of the cache you must first solve the mystery of Who Killed Mr. Boddy.
Who killed him? Was it Colonel Mustard in the conservatory with a lead pipe? Or maybe it was Miss Scarlet, daughter of Mrs. Peacock. Your task is to travel around Arcata and collect the clues needed to solve the mystery. Good Luck! (And bring a pen.)