.. “Pepper Hill” at Weeting is said to be so called because from its poplar-crowned summit “Oliver Cromwell peppered Weeting Castle.”
From ‘Norfolk and Suffolk’ by W G Clarke (1921).
However, in a letter to the Thetford and Watton Times on 20th October 1894, it’s mentioned “I have frequently heard children say that Pepper Hill was so called because of the pepper found there.” (Perhaps some peppery plant like sorrel? I think they’d be lucky to find some actual pepper :)