Italy is very famous for its sea. And Rome is actually very close to hundreds of kilometers of mostly sandy coast. You don’t necessarily need a car to find a nice beach. Trains and buses bring you within an hour to a lot of sea resorts north and south of Rome. But If you want to go where  Roman VIPS like to spend their holidays then you need to reach Sabaudia, Circeo and if you don’t mind jumping on a ferry to Ponza and its smaller islands, it will provide an unexpected and very exotic detour from your roman vacations.