After the 'Battle of Wits' Buttercup and Westley cross the moors in Sheffield at Carl Wark on Hathersage Moor. Higger Tor is visible on the Horizon.
Visit http://www.geograph.org.uk/photo/3261818 to see a map of the area. If you click on the map a 1:25 000 map will pop-up.
The Wikipedia page for Carl Wark can be found at https://en.wikipedia.org/wiki/Carl_Wark