Chateaus (castles) and mansion houses (residences) are a common part of village and town settlements in our conditions in the Czech Republic. Due to the interruption of ownership and property relations to these buildings during the 20th century, many of them lost their original or additional useful purpose, were abandoned and fell into disrepair and ruins. Nowadays, these chateau and mansion houses wish regeneration and renewal, and they have thus become an important historical, urban and social element in the development of the territory and cultural landscape. Due to the absence of a theoretical definition of this type of brownfield, the intention of this paper is to try to do this through a synthesis of expertise in the field of brownfields and the historical context of the existence of chateaus (castles) and mansions and grounds (areas). The intention is also to identify the historical milestones that contributed to the formation of the castle brownfields. The findings are inductively generalized in the created conceptual scheme of the genesis and restoration of chateau and mansion brownfields. The term castle brownfield was defined and the main historical milestones were emphasized, which significantly contributed to the emergence of this type of brownfield in the Czech Republic.