Archeological excavations at the monastery of Szermonostor started in 1970 under the supervision of Ottó Trogmayer followed later by other archeologists including Ferenc Horváth and Katalin Vályi. These works used the most up to date methodologies and tools providing thorough documentation of features and artefacts. The lithic material, which is the subject of this study was handed over to us for analysis by Katalin Vályi. Based on our results the studied building stones were of outstanding quality and must derive from quarries of the Buda, Pilis, Gerecse Hills. The stones were transported to the site on the Danube and the Tisza Rivers. Although the majority of the stones come from the mentioned areas, some specimens have proveniences in the eastern and western parts of the Balaton Highlands. The order of description of the studied samples followed that of successive geological ages from the Permian to the Pleistocene. Processing marks and alterations were also noted and described
