Maastricht Stone is a soft and porous, pale limestone from the Krijtland, a geological region with Late Cretaceous outcrops across the border of Belgium, The Netherlands, and Germany. It has a remarkably high porosity and low strength; however, the stone is very durable in a diverse range of outdoor applications. The stone has been used since Roman times, excavated in some opencast and many underground quarries. Its main use is situated in the period between the fifteenth and first half of the twentieth century. The local community has always been strongly engaged with the production of the stone and the resulting underground landscape, which has served for secondary purposes as shelter, mushroom cultivation, and tourism. Today, the region is appreciated for this particular landscape and the recognisability of the built heritage in Maastricht Stone. The stone is a preferred substrate for scientific research in stone conservation, due to of the homogeneity of the blocks from the last remaining active quarry in combination with its specific petrophysical properties. Therefore, Maastricht Stone is proposed as a ‘Global Heritage Stone Resource’ to augment its visibility and understanding.