Twenty seconds of The Wild North Coast, written for this very spot. On the tour it plays by itself as you arrive.
Portela is a mountain pass, the saddle where the road crosses from the dry, sunny east of the island over to the green, wet north. And because it's the hinge between two very different Madeiras, the view from here is one of the most rewarding on the island for the least effort: just pull over at the café and turn around.
Below you, the north coast opens up: the town of Porto da Cruz tucked against the sea, terraced vineyards stitched into impossibly steep slopes, and dominating it all, the enormous bulk of the Penha de Águia (Eagle Rock) rising 590 metres sheer out of the Atlantic. On a clear day the whole scene looks staged.
This pass has been the crossing point for centuries: farmers, ox-carts, traders moving between the two coasts. There's a reason there's an old café right here: this is where you stop, catch your breath, and take in how abruptly the island changes character from one side of a ridge to the other.
Local tip: grab a coffee (or a poncha if you're not driving) at the old café and use the terrace for the view. It's the perfect halfway pause on a scenic loop back from the east, and the light on Eagle Rock is best in the morning.