The remains of the roman Arena can be visited
Roman Theatre Virunum

On the Zollfeld near Maria Saal in Carinthia, Austria, lies the Roman Theater of Virunum. It represents the only known stage theater in the Roman province of Noricum, making it an archaeologically unique site.
History+
The Roman city of Virunum was founded around the middle of the first century AD under Emperor Claudius and served as the capital of the province of Noricum. It replaced an earlier settlement on the Magdalensberg and likely adopted its name. The city was strategically located on an important connecting road between the Adriatic and the Danube, built on a flood-protected terrace. Until the second half of the 2nd century, Virunum was the seat of the provincial governor and an administrative center.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Virunum_Arena_Nordteil_22092006_01.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 46.6980, 14.3671