Castelsardo is a medieval town in the north of the Italian island of Sardinia. The town is situated on a promontory overlooking the sea and is characterized by narrow, winding streets and historic buildings.

One of the most notable landmarks in Castelsardo is the castle, which dates back to the 12th century. The castle was built by the Doria family, who ruled the town during the Middle Ages. Today, the castle houses the Museum of Mediterranean Weaving, which showcases the textile traditions of Sardinia and other parts of the Mediterranean.

Another important site in Castelsardo is the Cathedral of St. Anthony Abbot. The cathedral dates back to the 16th century and features a striking bell tower and ornate interior decorations.

Castelsardo is also known for its traditional handicrafts, including basket weaving and ceramics. Visitors can explore the town's many shops and markets to find unique and locally made souvenirs.

The town is also located near some of Sardinia's most beautiful beaches, including Badesi and Valledoria, making it a popular destination for sun and sand seekers. Additionally, Castelsardo hosts a number of cultural events throughout the year, including the Feast of St. Anthony Abbot in January and the Medieval Festival in August.