Aquae Helveticae, Roman vicus / medieval / modern city

Aquae Helveticae was a Roman vicus on the site of present-day Baden in the canton of Aargau, founded shortly after the turn of the first millennium. Legionaries from the nearby fort of Vindonissa, roughly five kilometres away, discovered thermal springs along the river Limmat and constructed bath complexes that drew both soldiers and civilians. A community of traders and craftspeople grew up around the baths and persisted until the early 5th century, when the settlement was abandoned during the late Roman collapse. Medieval and early modern urban layers were subsequently built directly atop the Roman foundations, making Baden a rare palimpsest city where distinct historical eras physically overlap. The site is classified as a Category A cultural heritage site of national significance in Switzerland.