One of the oldest and most important churches in Milan. It was founded by Bishop Ambrogio in the 4th century, who later became the church’s patron saint. Only after his death was the church named after him, and his relics are kept there to this day.

The basilica has undergone changes over the centuries, but it still preserves treasures from the 4th and 5th centuries, such as a 4th-century sarcophagus adorned with figure reliefs and a golden mosaic in the Chapel of San Vittore.

The column capitals in the atrium (added in the 11th century by the Benedictine order) feature stunning carvings of religious scenes. A recommended starting point for your visit is the Porta della Pusterla gate, from where you can view the entire complex, including the bell towers and the atrium.