What is an area of land that has never been built on referred to as?

The term "Greenfield site" specifically refers to an area of land that has not been previously developed or built upon. This type of land is often considered for new construction projects, such as residential, commercial, or industrial developments. Greenfield sites are typically open land, which may include agricultural fields, forests, or natural landscapes, making them attractive for development due to the absence of existing structures and infrastructure.

In contrast, the other options may refer to land that is empty or unutilized, but they do not carry the same connotation of being untouched or ready for new development in the same way that Greenfield sites do. Undeveloped land can still include spaces that may have restrictions or existing disturbances, while vacant land could imply that a structure once existed but has since been removed. Raw land generally refers to land in its natural state that may or may not have been assessed for possible development, lacking specificity about its history of use.