Castro Verde is a municipality located in the Alentejo region of Portugal. It is situated within the Baixo Alentejo subregion and occupies a territory known locally as the Campo Branco, covering an area of 569.44 km2. As of the 2011 census, the municipality had a population of 7,276.
The region is characterized by specific local municipal markers placed along its borders. These markers are designed as stylized house profiles featuring an exaggerated window intended to allow visitors to see through into the surrounding panorama. The area is also recognized by the local designation "A Window on the Plains."