This is a historic street circuit placed in Porto Alegre, in the Brazilian state of Rio Grande do Sul. It hosted the "12 Hours of Porto Alegre" endurance event between 1963 and 1968.
Some photos:
Some years ago I've found some maps, but it was deleted, but the track looks like this:
As I've been trawling the Suggestions/Tracks forum to tidy it up a little bit, I've come across a few threads like this one that could do with an update, and I've somehow managed to burn three hours digging into this - even though as an historic road circuit now destroyed by normal urban processes it will never be eligible for Gran Turismo. Go me.
Anyway, the thread was originally titled Autodromo Cavalhada-Vila Nova and I couldn't find a thing on it. Probably not helped by the old language barrier.
However I was able to find the missing map in a book about the race it is supposed to have hosted: the 12 Horas, subsequently called the 12 Horas de Taruma after moving to a purpose-built course, Autodromo Internacional de Taruma, in Viamao near Porto Alegre 1971. The map is of course hand drawn and not oriented north... :|
Which led me to a second map... also hand-drawn and of the same orientation and suggesting that one was traced off the other:
Both maps refers to the course as the Circuito da Pedra Redonda - Circuit of the Round Rock - which is what I've changed it to, and describes the circuit as taking in the neighbourhoods of Cavalhada (per the original title), Ipanema, and Tristeza (the same as the video @CaravanSS76 posted). The road names are clear enough, and the book gives the start point for the 15km course as the Rua Otto Niemeyer.
Which juuuust about gives me enough to draw this approximation on present-day roads:
That's only 12km though, but it does take in all the roads mentioned and all the landmarks I can find, so I'd guess there's been a few road layout changes (one of which being the second major road, the Av. Wenceslas Escobar; it wasn't there before) over the past 60 years...
Anyway, it staged three races in 1962, 1963, and 1968, and then that was that. And Emerson Fittipaldi won the last one...
Confusingly there was a second street circuit in Porto Alegre at about the same time (1958-1968), and that was called Circuito da Cavalhada-Vila Nova, but it doesn't look like it's the one that hosted the 12 Horas as it's much shorter, and only in the Cavalhada area... but there looks like considerable confusion over that, so I'm unsure which track hosted what.
I can only find one approximate map for that, and the route shares only a small part of the course above:
