The rural landscape of Belgium abounds with ancient monasteries not far from which you can perceive, occasionally hidden under the vegetation, sometimes the silhouette of a smokestack, other times the shape of a saw-tooth roof. These remains are witnesses of the industrial fate that many rural monastic sites knew from the 19th century onwards. Sold as Biens Nationaux, as a consequence of the French Revolution (1796-1813), they took part in the early industrialization of Wallonia, second industrial power of the world in the 19th century after the United Kingdom. Coveted for their many assets (hydraulic energy, vast and robust buildings, significant land heritage), the secularized monastic estates located in rural areas were in fact particularly conducive to the establishment of industrial complexes whose activities continued, for the most remarkable, until the second half of the 20th century. The deindustrialization of these sites, initiated by the recurring economic crises of the 20th century, is now putting many buildings and industrial wastelands at risk. After having drawn up an inventory of Belgian monastic sites reused for industrial purposes in rural regions in the 19th and 20th centuries, the present contribution firstly aims to identify the challenges currently posed by this heritage, while examining the prospects for the potential enhancement of the industrial remains, which are often tenuous and mostly abandoned. The second step consist in determining the place given to recent industrial history (19th-20th c.) in the development (protection, restoration) of some of these sites. For instance, what has been the fate of the industrial buildings and sites in the legal heritage classification decrees? Do these prescriptions affect, positively or negatively, the preservation and development of industrial heritage? Is the “industrial abbey” also of interest to local communities, researchers and political actors, or is this interest in these sites fading away as they become deindustrialized? These issues are considered in the light of several examples from Wallonia such as the Abbey of Moulins (Anhée, Namur), reassigned as a copper factory (1831-1980), the priory of Oignies (Aiseau-Presles, Hainaut), reinvested in a glass making industry (1837-1956), or the Abbey of Val-Saint-Lambert (Seraing, Liège), which has housed a crystal factory since 1826. Through this perspective, we hope to offer new keys to reading as well as new avenues of reflection in the service of preservation and reassignment of rural industrial heritage. We also wish to make the scientific community and the authorities in charge of heritage protection aware not only of the recent industrial history of these monastic sites, but also of the heritage identity that derives from it.