Health facility in Raynes Park (3)
I believe the answer is:
spa
'health facility' is the definition.
(I've seen this in another clue)
'in raynes park' is the wordplay.
'in' indicates a hidden word.
'SPA' can be found hidden inside 'raynes park'.
(Other definitions for spa that I've seen before include "well" , "here for healthy holiday" , "Watering hole" , "town for his health!" , "here for the good of his health?" .)