Abstract Building stone is a significant product in most human communities. While some civilizations paid more attention to the aesthetics of the stone, others focused more on physical properties, especially durability, as well as the ease of transportation to construction sites. These latter issues determined which rocks were exploited, in preference to others, for centuries. Ancient Roman society became expert in constructing durable engineering projects (e.g. roads, bridges and aqueducts). Most of their projects were realized using local granites and most remain in excellent condition today. The historic cores of many European cities need to preserve their integrity, using the original building stone of the city both for new construction and for restoration. A supply of the original material should be preserved in order to avoid use of alternative building stones when restoring old monuments. In Salamanca, a specific unique granite was used to build many of its monuments that are now preserved as part of the UNESCO World Heritage Site. An attempt to preserve this architecture and restore it, when needed, with the original material is the main focus of our paper, as some experiences using other types of rocks have led to unfortunate results.

Abstract Paleozoic calcitic marbles are found in the Estremoz Anticline, Ossa-Morena Zone (Southern Branch of the European Variscides in Portugal). This 40 km NW–SE structure presents outcrop continuity and intense mining activity since the Roman Period. The structure has a Precambrian core and the younger rocks are from the Devonian Period. The marbles occupy an intermediate stratigraphic position in the Cambrian age Volcano Sedimentary Sequence. The Variscan Orogeny had two pulses with different intensities under ductile and brittle tension fields. The Alpine Cycle also caused more fracturing of the marbles. The geological features imprinted in the marbles are beautiful aesthetic patterns highlighted when used as dimension stone. Since the Roman period, pieces of art made with Estremoz Marble were exported abroad and can be found in museums and archaeological sites throughout Europe and North Africa countries. Present day, Estremoz Marble objects can be found all over the world. The very rich marble based heritage is omnipresent in cities, and the countryside is marked by intense mining activity side by side with rural industries; therefore the region has unique characteristics allowing the development of integrated industrial tourism routes, promoting sustainable development of industrial, scientific and technological cultural opportunities. The historical and widespread application of these marbles in national and international monuments, some of them already part of the UNESCO World Heritage Sites, is a condition to propose them as Global Heritage Stone Resource for their international recognition.