Spectacular narrow road.
Not long (about 8km section), but the most fun you can have on the island (since it doesn't have a race track).
The road to get there from the north part (going up from Ribeira da Janela) is nice to but the surface is in bad shape.
Trucks are not allowed in this road, so the asphalt is in perfect condition.
Things to watch out: cows on the road and occasional fog.
Also keep in mind that this is a tourism hot spot, so sometimes (mostly in summer) you can expect some rental cars cruising at slow speeds.