I stayed in Grosseto as an au pair, so I’m afraid I can be little help on accommodation. A quick Google has shown me that it does exist, a few B&Bs on TripAdvisor, that I wanted to confirm before persuading you to go there. Which I can now do.
Grosseto is a stunning quiet town surrounded, while I was staying, with sunflower fields. If you’re staying in the centre you might not have a chance to relax and walk about the fields as I did (with the mountains – or hills but hey – in the distance). Without a car the buses tend to appear only for school hours, though the main roads are possible (if a tad terrifying) to bike down. And what would draw you to take the terrifying pedal trip down main roads of speeding locals trying to get home? Sunflowers, sure, but you live near a florist I’m guessing, you’ve seen them before. A terrible argument, no one has seen fields of bright yellow flowers, growing above your head and stretching off to the distance, if they have only ever seen one wilted bouquet. However, if you do insist on this argument, then I will tell you that outside Grosseto lies the beach. Or really, quite a few beaches. Stunning, sand covered, blue-watered beaches.
Some are more touristy and some are more empty with higher waves and sprouting grass. A challenge, I think, to get to without a car – but something I’m sure any B&B in the area is used to being asked. If you are heading to the emptier beaches, remember to bring an umbrella (or some sort of shade). The touristy beaches are covered in sun loungers and umbrellas if you wish to rent one. Reading on the sand with the blue waters ahead is stunningly relaxing.
Grosseto town itself is also wonderful. Not busy, not loads to see, but cute and with a delicious slice of pizza for one euro. There are quiet parks to sit in (and read of course), shops, bars and cafés. I remember sitting outside one in the sun with a lemon beer. Grosseto is also where I had the best hot chocolate I have ever tasted, which I have not yet perfected myself (I give up, I shall just have to find the café again). On one of the main streets I stopped in a small shaded café and, having already had far too many coffees that holiday, ordered a cioccolata from the menu scrawled across the back wall. It was like chocolate soup, and I started off by sipping it with my teaspoon. Have you seen the film Chocolat? This curved bowl/mug of chocolate belongs in that film.
Grosseto is a lovely sunny town to spend time in, even if just for a day trip. One day I hope to stay longer in the town itself, but for a quiet holiday it is wonderful. Except one of the things I loved was its quiet peacefulness, so perhaps I do not want to persuade you to go. No, I have changed my mind. Go to Pisa instead. Its towers are more leany.