Avenches is a Swiss municipality in the canton of Vaud, located in the district of Avenches, of which it is the capital. Avenches is located on a hill, isolated in the Broye valley, 12 km north-west of Fribourg. The village Donatyre (505 m), south of Avenches, belongs to the municipality of Avenches, partly until 2006, and entirely since the municipality of Donatyre merged with Avenches. Avenches is built on the site of the Roman town Aventicum, which was the most important in Switzerland.