Eagles Canyon Raceway near Decatur, TX has a corner that goes into the canyon. It is a downhill off camber curve, that drops way down several stories. When I hit the line just right it was a blast, if I was a bit off line the camber really got bad, and I was going sideways looking at the curve through the driver's side window, staying on the throttle to drift through the apex. That was exciting, and I tried real hard to not repeat that.
It is a private track where rich folks can keep their car, and go run all day if the they want. They will rent it out to a private group to use for the day.
https://en.wikipedia.org/wiki/Eagles_Canyon_Raceway