It is a monumental aggregate located in via San Domenico in the ancient village of Milazzo.
Building work started in the mid-500s in the area that housed the church of San Leonardo, and the works continued until the following century. Recent restoration works have brought to light a reservoir from the Roman age, which demonstrates that there were settlements in the city prior to the medieval Castrum. The reservoir is thought to have had a glass roof. The church was the seat of the Inquisition Tribunal.