Cabo Girão
At 1,900 feet, Cabo Girão is on one of the highest sea cliffs in the world, and the observation platform—with a clear glass floor so you can gaze straight down—gives you a bird's-eye view down to the coast. From here you can see the ribbons of terraces carved out of steep slopes where farmers daringly cultivate grapes and garden vegetables. During high season, the walkway can get crowded with bus tours, so get there early if you want to beat the crowds.