The red onion of Acquaviva is known by sight: flat, up to fifteen centimetres wide, sweet enough to eat raw in slices like fruit. A Slow Food Presidium and civic pride, it is celebrated each October with a festival that fries it, stuffs it and sings it.
In the town's restaurants it fills the onion calzone, focaccias and summer salads. Passing through in season, buy it braided straight from the fields: the sweetness comes from the aquifer water that names the town.