This is the trig point sitting on top of Blackchester Hill (214m) in Alnham and #11 in the book. It's around a 1.5km walk on a restricted path through the fields.
It's pretty easy to get to and you can either head straight south and then west or pick your way through the fields.
Thanks to Pete McNaughton for the photos and information. You can also join Pete on a virtual walk to the trig point too.