Westerners in Kalahari organise pleasant jaunt, exploring hill in South Africa (5)
I believe the answer is:
kopje
'hill in south africa' is the definition.
(South African term for a hill)
'westerners in kalahari organise pleasant jaunt exploring' is the wordplay.
'westerners in' suggests taking the first letters (the letters furthest left or 'west' in the word).
The initial letters of 'kalahari organise pleasant jaunt exploring' is 'KOPJE'.
(Other definitions for kopje that I've seen before include "Hillock of South Africa" , "Small hill of S Africa" , "South African hill" .)