Advice to visit a S American plain or plateau (9)
I believe the answer is:
altiplano
'plateau' is the definition.
(the altiplano is a Central American plateau)
'advice to visit a s american plain' is the wordplay.
'advice' becomes 'tip' (a tip is a piece of advice).
'to visit' means one lot of letters goes inside another.
's american plain' becomes 'llano' (a llano is a South American plain).
'a'+'llano'='allano'
'tip' placed into 'allano' is 'ALTIPLANO'.
'or' acts as a link.
(Other definitions for altiplano that I've seen before include "High" , "South American plateau" .)