Plataia (Platea, as it is commonly spelled in English) is one of the key sites for Historians, Classicists, and Archaeologists with interest in Greek antiquity. Plataia fought with Athens at Marathon and itself is the site of a key battle in the third Persian war. This site report includes the full text, translation, and commentary on Diocletian's De Pretiis Rerum Venalium, copies of which have been found elsewhere. Other inscriptions are included along with the report on a ruined Byzantine church and the physical remains of the battlefield. This is the first report on one of the most important archaeological sites in Greece and lays groundwork for subsequent excavations.