Ariano lies at 817 m above sea level. The present ruins of the Castle that was built in Norman times on the remains of an earlier Castle (built during the Lombard domination) dominate the hilltop. The first documented mention of the fortress in the Middle Ages dates back to 574.
Over the succeeding centuries, ownership of the castle passed from hand to hand - Ruggiero II, Enrico de Vaudemort and Francesco Sforza de Cotignola. After the devastating earthquake of 1456, the fief was purchased by Alberico Carafa.
The structure of the Castle was severely damaged by various earthquakes that struck Aiello in 1550, in 1638, in 1694 and in 1732. Today we can see four cylindrical towers, the Keep and curtain walls.