Shared Mining Heritage for cross-border territorial regeneration. The case of the Grünmetropole in the Three Countries Park

The remains of the extractive industry have long been seen as a stigma to be concealed[1]. Nowadays, several projects attribute to Mining Heritage (MH) the physical and cultural potential to become the backbone of the sustainable economic and ecological resurrection of spatially fragmented territories[2]. Indeed, in opposition to the continuity of the underground layers (invisible), the exploitation of the subsoil shaped an extremely fragmented surface landscape (visible)[3]. MH, charged with cultural meanings and collective memories, represents the link between visible and invisible layers. The Three Countries Park (3LP) - heart of the Euregio Meuse-Rhine (EMR), a trinational region (BE-NL-DE) covering an area of about 5000 km² - is an emblematic example of how European cross-border territories made it through landscape fragmentation as a result of the mining industry[4]. In 2008, Agence Ter drew up the Grünmetropole Masterplan based on the characteristics and identities that the subsoil gave to this cross-border landscape[5]. The development of the masterplan took place in a very open dialogue process, in the form of workshops with local actors and associations to test how shared MH could help rebuild common links, reconstitute memories and collective values, at the service of territorial development in fragmented environments[6]. The originality of this case study lies in the character of an "open project"[7] given to the tools for the progressive transformation of the territory. The 3LP is thus a "laboratory" for the monitoring of an on-going project, accompanied by an agency for management which plays the role of the "project guardian"[8].