Spiaggia di Marina di Albarese (the wild beach) is in a nature reserve and so numbers are restricted during the day and it closes just after sundown. There are some refreshment vans and loos in the 'pineta' (pine forest) but no other amenities and if you want to walk the 2km to the end of the beach, take your own water, food and an old sheet (nick one from the house!) to make yourself some shade. There's a barrier at the entry/exit which registers your number plate as you enter and then you type it into the meter when you leave to pay. It gets very busy in July and August.
Principina a Mare is an easy beach to rent umbrella and sun beds from (we use Bagni Grifomare). Parking is cheapish and payable on the parking app 'easypark'.
Bagni di Domiziano, on the Argentario peninsular (take swimming shoes as there are sea urchins) and invent your own parking on the side of the road. Here you can snorkle over parts of Nerone's family villa. Also on the Argentario peninsular, just through Porto Santo Stefano, is the beach of Siluripedio which has a car park too! Lovely clear water for snorkeling (there's a bag of asssorted swim shoes in the house upstairs).
Cala Violina, between Punta Ala and Puntone di Scarlino, park in the paid car park in the field and then it's about a 500m walk to the beach through the woods. Lovely clear water, but avoid in July and August as it can get super busy - or get there early!
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