Thunderous African spectacle? Call for a visit to be arranged (8,5)
I believe the answer is:
victoria falls
'thunderous african spectacle?' is the definition.
(African waterfall)
'call for a visit to be arranged' is the wordplay.
'to be arranged' is an anagram indicator.
'call'+'for'+'a'+'visit'='callforavisit'
'callforavisit' is an anagram of 'VICTORIA FALLS'.
(Other definitions for victoria falls that I've seen before include "Current attraction" , "Zambezi River spectacle" , "Italian sports-car company" , "Zambezi cataract" , "drop of water" .)