Platt is a village in the Zellerndorf administrative community in the district of Hollabrunn, Lower Austria, in northeast Austria. It is notable for its position on the Diendorf fault line and for its immediate vicinity to the site of one of the most significant Celtic settlements in Central Europe, situated on the southern slopes of the nearby Sandberg ridge towards the neighboring village of Roseldorf.HistoryThe Platt area shows signs of human habitation that date back to late neolithic (Funnelbeaker culture) and early Bronze age (Unetice culture) times. Prehistoric culture reached its peak during the early and middle La Tène period, around 300 B.C., when the large (20-40 ha) Sandberg Celtic city existed here on the southern slopes of the nearby Sandberg ridge. Systematic archeological excavations that have been ongoing since 2001 continue to reveal information on this recently recognized and highly significant settlement from the Iron Age, which at its climax comprised at least 450 buildings and included a halidom district with several cult sites.The village of Platt was first documented in 1185 (as Plade), and grew from 56 buildings in 1590 to 187 in 1850, when the population reached 1,202 and the village became an independent administrative community. From this time onward the headcount dropped continually, reaching a minimum of 398 in 1991 and rising only marginally as a result of weekend residences being built, mainly by citizens of Vienna which is about 75km away to the southeast. In 1967, the local administration of Platt was moved to Zellerndorf.