National Park regenerated green site (9)
I believe the answer is:
serengeti
'national park' is the definition.
(I've seen this before)
'regenerated green site' is the wordplay.
'regenerated' indicates an anagram.
'green'+'site'='greensite'
'greensite' is an anagram of 'SERENGETI'.
(Other definitions for serengeti that I've seen before include "Tanzanian plain renowned for its wildlife" , "reserve for game" , "area of the plain" , "Wildlife-rich region of Africa" , "region in Tanzania" .)