This is the Offroad Big Hill Ramp. Despite it being termed as the Big Hill Ramp, it's actually not that big. It's bigger than the Off-Road Low Hill Ramp, though. Heavy cars like EL KING and MASHEEN will have a harder time doing a stunt off of this.
The ramp gently slopes up to the peak on one side, with the other side sloping up directly to the peak. With the ramp's size, it is probably better to use the sloping side to do stunts off of.