The cache is not at the above coordinates but within 2 miles.
If you have not yet completed the adventure lab, you will need to complete all 5 stages to reveal the bonus coordinates.
If you have completed the Cranbrook Town and Country Park Adventure Lab, congratulations!
It would be easier to update the bonus location after completing stage 5 of the adventure lab, as you will be walking past/near the cache on route back to the train station and be returning to your car.
Please be stealthy when retrieving and hiding the cache.
Happy hunting.