The first thing that greets you is the sound: a hollow clap of surf against limestone, then a guide’s steady voice and the sight of a big colored Fiat Ducato tucked into the small parking lot of Carvalho Beach. You push off in a two-person kayak and the ocean immediately asserts itself — gentle nudges at first, then, as you skirt the cliffs, a stronger shoulder that seems to want to show you every groove and window the sea has carved. The route bends, a tunnel in the rock opens like a doorway, and sunlight pours into the mouth of Benagil’s famous algar. Your guide angles the kayak so the camera can catch the light inside; by the time you paddle back to the soft sand of Carvalho, your phone and the free 4K photos are full of impossible blue.