Castello di Santa Severa is a medieval castle located in the town of Santa Marinella, about 50 km north of Rome, Italy. The castle was built in the 10th century on the site of an ancient Roman fortification and was initially used as a defensive outpost against Saracen pirates.

Over the centuries, the castle was expanded and renovated by various noble families, including the Orsini and the Chigi. Today, visitors can explore the castle's various rooms and halls, which are decorated with frescoes and other works of art. The castle also hosts exhibitions and events throughout the year, including historical reenactments and concerts.

In addition to its historical and cultural significance, Castello di Santa Severa is also known for its beautiful seaside location. Visitors can take a stroll along the castle's ramparts and enjoy stunning views of the Mediterranean Sea. The castle's beach is also a popular spot for swimming and sunbathing.