In order to find this bonus cache you must successfully complete my Raleigh’s Lost History Adventure Lab. If you aren't familar with Adventure Labs you can read more about them here in this Help Center article. If you do not have the app on your phone, go to the app/play store and download if for free. If you already have the app, go enjoy the historic tour of some sites where Raleigh used to have fun and play.
If you have already done the tour, then you have the coords to go and find this one, so quit wasting your time reading all of this. 
Here's the link to the Adventure. There is also a QR code in the gallery.
There are three unactivated tokens in the cache for the first three finders. There is also a small Signal trackable that I have held onto for far too long, so please move it along.