None of the legal acts applied in the Polish monument protection system, ranging from the Regency Council Decree of 1918 to the Act of 2003, allows for transforming historic monuments and sites. This provision applies, paradoxically, unless a competent historic preservation officer approves such transformations. In other words, under the aforementioned acts, it is possible to make any modification to the existing historic monument or site, provided that a historic preservation officer issues an appropriate permit. Each of these legal acts provides framework for classifying historic monuments and sites, e.g. by introducing various forms of protection, classifying monuments and sites under various categories – immovable, movable, archaeological, etc. Therefore, classification is real. There are so many different historic monuments and sites falling under a great number of categories that it is impossible to provide them with real, even diversified protection. It is therefore necessary to implement such a classification of historic monuments and sites that would allow state and regional historic preservation officers and representatives of local government administration to carry out actions aimed at protecting properties and places of great historical significance. The recommended classification is a starting point for discussing methods, criteria, and rules governing classification of historic monuments and sites. Additionally, it will ensure appropriate protection.