Castello Estense is a medieval castle located in the city of Ferrara, in northern Italy. It was built in 1385 by Niccolò II d'Este, Marquess of Ferrara, as a symbol of his power and wealth. The castle was later enlarged and renovated by different members of the Este family, who ruled Ferrara for more than three centuries.

The castle is surrounded by a moat and has four large towers at the corners, which were used both for defense and as living quarters for the nobility. The main entrance is through a drawbridge, which leads to a large courtyard with a beautiful fountain in the center.

Inside the castle, visitors can explore a number of rooms that have been preserved in their original state. These include the Sala dei Giochi, a hall decorated with frescoes depicting scenes from ancient mythology; the Sala degli Specchi, a ballroom with beautiful mirrors and stucco decorations; and the Sala dei Boi, a room used for banquets and other festive events.

The castle also houses several museums, including the National Museum of Italian Judaism and the Shoah, which is dedicated to the history and culture of the Jewish community in Italy; the Museum of Ancient Art, which contains a rich collection of paintings and sculptures from the 14th to the 18th centuries; and the Museum of Risorgimento and Resistance, which documents the struggle for Italian unification and the resistance movement during World War II.

Today, Castello Estense is one of the main tourist attractions in Ferrara and a symbol of the city's rich cultural heritage.