National Park: green site abroad (9)
I believe the answer is:
serengeti
'national park' is the definition.
(I've seen this before)
'green site abroad' is the wordplay.
'abroad' indicates an anagram.
'green'+'site'='greensite'
'greensite' with letters rearranged gives 'SERENGETI'.
(Other definitions for serengeti that I've seen before include "Green ties (anag.)" , "Vast plain" , "Tanzanian plain renowned for its wildlife" , "where lion holds sway?" , "Wildlife preserve (and National Park) in Tanzania" .)