Cala Granu is the nearest beach to Porto Cervo proper and the only one you can comfortably walk to from town. It is a small, sheltered bay of coarse pale sand backed by a few villas and a hotel — not the prettiest beach on the coast, but the most useful one. The water is calm and shallow, good for an early swim before driving out to the better-known beaches further south.
The car park is small and free, and you can normally find a spot even in August if you arrive before mid-morning. A short rocky walk around the headland leads to a second smaller cove that is usually empty.