Place covering wild green summit in national park (9)
I believe the answer is:
serengeti
'national park' is the definition.
(I've seen this before)
'place covering wild green summit in' is the wordplay.
'place' becomes 'set' ('set' can be a synonym of 'place'**).
'covering' is an insertion indicator.
'wild' indicates anagramming the letters.
'summit' says to take the initial letters (I've seen 'summit of' mean this).
The initial letter of 'in' is 'i'.
'green' with letters rearranged gives 'renge'.
'set' enclosing 'renge' is 'serenget'.
'serenget'+'i'='SERENGETI'
(Other definitions for serengeti that I've seen before include "African ecosystem" , "region in Tanzania" , "Tanzanian plain renowned for its wildlife" , "Tanzanian wildlife area" , "where lion holds sway?" .)