Monte Cassino Abbey is a Benedictine monastery located on top of a hill in the town of Cassino in central Italy. It is famous for its long and rich history, architectural beauty, and for being the site of one of the most important battles of World War II.

The abbey was founded in 529 AD by Saint Benedict of Nursia, the founder of the Benedictine order. Over the centuries, it grew in wealth and importance, and became one of the most influential monasteries in Europe. The monastery was destroyed and rebuilt several times throughout its history, with the most devastating destruction occurring during the Battle of Monte Cassino in World War II.

The Battle of Monte Cassino was a series of four Allied attacks on the German-held monastery from January to May 1944, with the final attack resulting in the destruction of the monastery. The battle was a key moment in the Allied invasion of Italy and is considered one of the most important battles of World War II.

After the war, the abbey was rebuilt according to the original plans, and its historic library was restored. Today, it is a major tourist attraction and a functioning Benedictine monastery. Visitors can tour the abbey's museums and libraries, attend mass, and take in the beautiful views from the hilltop location.