The Micia site, is recognized as an archaeological civil settlement that was inhabited, and soldiers from several troops, were stationed in the Roman camp. From the end of the 2nd century AD, the civil settlement was rebuilt, with residential areas, industrial areas, port, public baths (civilian and military), amphitheater, religious areas (temples) and enjoying the facilities of a city. In this regard, the present work will first address the composition of the samples taken from the Roman monuments identified in Micia area and will highlight for the first time for this Roman site the presence of a form of tremolite-asbestos. This paper analyzes for the first time the presence of traces of tremolite-asbestos in stone samples collected from Roman monument buildings extracted from quarries near the city of Deva and used in civil, military and funerary structures from Micia. Highly performant and sensitive analytical techniques have been used to put into evidence the tremolite-asbestos species, to identify the structure, composition and morphology of these minerals inside of the building materials from Roman monuments, as follows: optical, stereo and scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence with wavelength dispersion (EDXRF), FTIR and Raman spectroscopy, thermal analysis (TGA/DTA). It is presumed that tremolite-asbestos species has been included in the material layers used as mortars at Micia settlement in order to protect these monuments.