3rd cache in the Mega Day series. Please see cache 1 for full details of the series. The above coordintaes will lead you to an emergency telephone number: 0800 ABCDEFG. Hope you have good eyesight 
Cache can be found at:
N51 13. (F-C) (F-D) A
E000 23. (F-B) (G-E) (F-G)
Cache is a double sized film pot