Aventicum, Roman city - Avenches, medieval-modern city, Roman archaeological site in Avenches, Switzerland.

Aventicum is a Roman archaeological site in Switzerland containing the remains of an ancient city with walls, an amphitheater, and bathing facilities from the 2nd century. The surviving structures show how large this settlement was and how important it functioned as a regional administrative hub.

Aventicum was founded around the turn of the era as the capital of the Helvetii, on the road from Italy to Britain. In 69 AD the Helvetii backed Galba against Vitellius; the Legio XXI Rapax sacked their settlements and occupied Aventicum. Vespasian, who had spent part of his youth there, raised it to a colonia in 72 AD, and it grew to over 20,000 inhabitants. Marius Aventicensis moved the bishopric to Lausanne after the Council of Mâcon in 585.

The name Aventicum comes from Aventia, a Helvetian spring goddess. The city was the capital of the Civitas Helvetiorum, and Tacitus called it Caput gentis. Finds from the excavations, including marble portraits of the Julio-Claudian imperial family made in Rome, are shown in the Musée Romain in the tower above the amphitheatre entrance.

An on-site museum displays excavated items like coins, inscriptions, and everyday objects that bring the ancient world to life for visitors. You can explore the exposed structures across the grounds and get a sense of how the original city was laid out.

The name Aventicum comes from Aventia, a Helvetian spring goddess, and the town may have been called Forum Tiberii before becoming a colonia. A stone found in the 17th century records the title Colonia Pia Flavia Constans Emerita Helvetiorum Foederata, though some scholars suspect the inscription is a forgery.