Spanish beach's sport area (5)
I believe the answer is:
playa
'spanish beach's' is the definition.
(I've seen this before)
'sport area' is the wordplay.
'sport' becomes 'play' ('play' can be a synonym of 'sport').
'area' becomes 'a' (maths abbreviation).
'play'+'a'='PLAYA'
(Other definitions for playa that I've seen before include "piece of land liable to flood" , "Expanse of dry land" , "bed in Spain" , "lake after rainfall" , "Spanish beach" .)