The Spanish Mill (Mulino Spagnolo) stands as a solitary sentinel, the last of nine mills that once dotted the Sienese landscape in the 15th century. These mills were crucial for grinding wheat and producing flour, forming the backbone of the local economy. Their construction highlights the engineering prowess of the era, designed to efficiently process agricultural yields.

When Orbetello became the capital of the Presidi State in 1557 under Spanish rule, the mill underwent a significant transformation. To harness the abundant winds that swept across the lagoon – a mix of the strong Mistral and the warm Sirocco – sails were ingeniously added. This adaptation not only increased the mill's efficiency but also transformed its appearance, making it a unique blend of historical function and adaptive design. The fact that this single mill has survived centuries of change and environmental factors is a testament to its robust construction and the community's efforts to preserve its heritage.

Today, the Mulino Spagnolo is more than just a historical artifact; it's a symbol of resilience and a picturesque landmark. Visitors often comment on the beautiful atmosphere it creates in the lagoon, a sentiment echoed by those who have seen it multiple times. It offers a tangible connection to the past, allowing visitors to imagine the bustling activity that once surrounded it and appreciate its enduring presence against the backdrop of the tranquil waters.