Where do you recommend staying in the Tuscan Maremma?

For a first stay, I would choose Castiglione della Pescaia if you want to enjoy the beaches and have restaurants and shops within walking distance; for the south of the region, aim for Orbetello or Porto Santo Stefano. The Maremma is vast: it's better to choose your accommodation based on your priorities rather than exploring everything from a single base.

In Castiglione, you are close to the sandy beaches and about 25 km from Grosseto. To explore the Maremma Park, look instead at the agritourisms aroundAlberese : it's quieter, but you will depend more on the car and access to some beaches is regulated or has limited parking. In the south, Orbetello works well for reaching the lagoon, the Giannella and Feniglia beaches and the Argentario; Porto Santo Stefano is more oriented towards the harbour and the coves.

If you prefer villages, thermal baths and the countryside, search around Manciano or Saturnia, often in agritourisms. In return, the sea is far away: Saturnia–Orbetello is about 55 km and nearly an hour's drive. I would book early for July and August, especially on the coast; off-season, the inland area is more convenient for enjoying walks and hot springs. A car is highly recommended, particularly for rural accommodations.