Vadstene Castle was built by King Gustav I in 1545 to protect Stockholm from possible attacks of the Danes from the south. The fortress consisted of three small stone houses, standing on the shore of Lake Vetern, three broad trees, courtyard, moat and four round cannon towers. The original ramparts were demolished in the 19th century, these trees were discovered only in 1999, and the original stone buildings now form the first floor of the castle. Castle Vadstene well preserved and today is one of the best examples of Swedish architecture of the Renaissance.

The restructuring of the fortress into a Renaissance chateau began in the 1550s when Prince Magnus became the Duke of the province of Östergötland. Duke Magnus was suffering from mental illness and was the only son of Gustav I. August 22, 1552 King Gustav I got married for the third time at Catherine Stenbock in the castle Vadstena. An interesting fact that one of the banquet rooms of the castle called the Wedding, although its construction has not been completed for the wedding. Magnus died in 1595 and was buried in the church adjacent to the castle of the Abbey. Construction of the castle was completed in 1620. Until 1716 he was a royal palace, but later monarchs lost interest in him, and it was used as a barn to store the grain.

Since 1899, the castle began to gradually transform into a museum. Today everyone can see the historical exhibits on the first floor of the castle, to visit one of the four gun turrets on the second floor (it is closed in the summer), and the third floor are decorated with furniture and paintings of 16-17 centuries. In addition to the museum in the castle are also located the Tourist Information Centre, Office of International Academy of Vadstena and the county archive.