A Caledonian race venue? (5)
I believe the answer is:
ascot
'race venue?' is the definition.
'Ascot' can be an answer for 'race' (Ascot is a racecourse). I'm not sure about the 'venue?' bit.
'a caledonian' is the wordplay.
'caledonian' becomes 'Scot' (Caledonia was the Latin name for Scotland).
'a'+'scot'='ASCOT'
Can you help me to learn more?
(Other definitions for ascot that I've seen before include "English horse racing venue on coast" , "Berkshire town, famous for horse racing" , "Tosca (anag) - racecourse" , "sporting venue" , "Fungus affecting wood" .)