According to the OS, (whether this is the case of not can be left for the finder to decide or research for themselves ;-) ), Applepie Hill is the source of the River Pang. You probably won't see any water here, and our Compton one now has been renamed. We did know that the source was further back, but at the time of placing the series, there wasn't a lot of water flowing in the Pang.
There is a bonus with the cache - it is right by a trigpoint! Don't forget to have a look into the field and see the fabulous views. You can park really close, so this is a nice cache and dash.