The Grand Hornu, Bois-du-Luc, Bois du Cazier and Blegny-Mine, as a entity, are shown alongside other Walloon properties already inscribed (elevators of the Canal du Centre, Walloon belfries, Notre Dame Cathedral Tournai and mining Neolithic Spiennes) on the prestigious World Heritage List

Further, the four sites form a coherent whole that justified their inclusion in series. This registration is a real recognition of the history, diversity and wealth of major mining sites of Wallonia and Walloon mining heritage in general.

This recognition is the result of a constructive collaboration work conducted throughout the application by the actors working on the four mining sites in synergy with the Walloon Region. However, it is only a stage in the form of challenge in the mission of conservation and development in which sites managers are committed and all the operators and institutions concerned with areas included in the registration.

As part of its 36th session, held in St. Petersburg in 2012, the World Heritage Committee decided to include the major mining sites of Wallonia on the World Heritage List. For the four sites, this registration is an opportunity but it also represents a challenge for the future. Indeed, the sites are bound by there in a challenge in the long term.

According to the definition established by the World Heritage Committee, the outstanding universal value means cultural/natural so exceptional as to transcend national boundaries and to be of common importance for present and future generations of all humanity. This means that sites recognized as world heritage belong to all peoples of the world and embody exceptional examples of the diversity of culture and wealth of nature.

To be included on the World Heritage List, sites must be of outstanding universal value and meet at least one of the ten selection criteria set by UNESCO. The criteria met by all composed by the four sites are the II criteria (indicator of an interchange) and IV (Example of a prominent or significant stage(s) in human history).

The four sites condense on a small space all aspects of mining heritage, technological, social, architectural, and complement each other. Together they represent a place of cultural confluence who assimilated contributions (exchanges of technologies and know-how humans) from diverse backgrounds and has had considerable influence in Europe and in the world.

Exploiting the "coal field" that goes from Whales to the Basin of Aachen, the four sites cover the same chronological period (the early nineteenth to the late twentieth century). The formed together also a microcosm of the Industrial Revolution. The different stages of technological development are all represented, as well as changing social relations.

The sites, the quality, diversity, originality and richness of their components also meet the standards of integrity and authenticity required by the World Heritage Committee.