Cava dell'Isola is a compact cove on the northern edge of Forio, sheltered between two low headlands and facing southwest. The sand is dark — mixed volcanic and silicate, typical of this stretch of coast — and the water is calm behind the promontory, making it a good choice when Citara is exposed to swell. It is smaller than Citara and receives a fraction of the visitors, which is recommendation enough in August.
The beach has a single lido with chairs and umbrellas for hire; there is also a free section. A bar operates in season. The cove is easily reachable on foot from Forio centro in around 15 minutes, making it the most convenient beach for anyone staying in town. The sunsets from the shoreline here, with the town's watchtowers visible on the headland behind you, are worth staying for.