Praia do Costão tucks into the rocky promontory south of Canto da Praia and is the most picturesque of Itapema's beaches: a small horseshoe of sand walled by green hills, with clear water and an absence of the high-rises that crowd Meia Praia. Access is on foot along a marked trail from Canto da Praia — roughly fifteen minutes' walk — or via the road that runs around the headland.
There are no kiosks, no umbrellas for hire, and no lifeguards: bring water, bring shade, and check the tide. Best in the morning before the wind picks up. The snorkelling around the rocks at either end is decent for the south Brazilian coast.