This is a short three stage multi with two very close locations for you to gather information, and then visit the final location to look for the cache. All locations are within walking distance of each other, and while it is a public location, in general it is not very busy.
Stage 1:
At stage 1 you will find a large carving formed out of an old tree. Count the number of carved bees. This number is A
Next look for two letters carved into the base of the tree. Take the sum of the values of these letters and this will be BC
Stage 2:
At stage 2 you will find a plaque to the right of the front door with the title "Whitby Centennial Building". How many years did this building serve as the County Court House. This number is EDF
Now for the math
North Coordinates West Coordinates
( ABC / 2 ) + 174 = GHI DEF + 514 = JKL
The final cache is located at N43 52.GHI W 78 56.JKL