Within a stone's throw of Barcelona's Circuit de Catalunya lie two defunct World Championship grand prix circuits - Montjuich Park and Pedralbes - reminding us that for every new venue that joins the circus, there are myriad others that have faded into memory.
The below list is about picking the greatest tracks from among these 40-odd circuits, some of which are still operating in one form or another, some of which are long gone, that once played host to the greatest drivers in the world.
When it came to selecting the top 10, those holding only non-championship races have been disregarded, as have pre-war grand prix venues.
As for the main criterion used, it is all about the biggest drivers' challenge, which is why we make no apology for the dominance of classic road courses. It is also why some great 'event' races - such as Long Beach and Adelaide - missed the cut.