Carnaval site (3)
I believe the answer is:
rio
'carnaval site' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rio that I've seen before include "Manchester United player in South American city, in short?" , "Spanish word for river" , "Location of next Olympic Games, in short" , "A Mexican river, may be grande" , "(Golfer) in the sand" .)