Plain green site for recreation (9)
I believe the answer is:
serengeti
'plain' is the definition.
(I know that Serengeti is a plain)
'green site for recreation' is the wordplay.
'for recreation' indicates an anagram (I've seen this in other clues).
'green'+'site'='greensite'
'greensite' is an anagram of 'SERENGETI'.
(Other definitions for serengeti that I've seen before include "Afr. plain; green site (anag.)" , "where lion holds sway?" , "Tiger seen in Tanzania's great National Park" , "Wildlife-rich region of Africa" , "African plain noted for wildlife" .)