Place of many races where you'll see a northerner (5)
I believe the answer is:
ascot
'place of many races' is the definition.
(Ascot is a racecourse)
'a northerner' is the wordplay.
'northerner' becomes 'scot' (someone from Scotland).
'a'+'scot'='ASCOT'
'where you'll see' is the link.
(Other definitions for ascot that I've seen before include "English course" , "racing centre" , "Royal race course" , "Where ladies wear new hats" , "Racecourse with royal associations" .)