Carnuntum

Carnuntum, some 40 kilometres east of Vienna, was the capital of the Roman province of Pannonia Superior and a legionary base guarding the Danube frontier. At its height it held around 50,000 people, more than any other Roman settlement in what is now Austria. The open-air museum at Petronell rebuilt an entire city quarter on its original foundations, with functioning Roman houses, workshops and heated baths that can be entered. Two amphitheatres survive, the larger seating some 13,000 spectators, and the Heidentor triumphal arch still stands in the fields to the south. The Museum Carnuntinum in nearby Bad Deutsch-Altenburg is the largest Roman museum in Austria. Carnuntum became part of the UNESCO Danube Limes World Heritage Site in 2021.