Castle in Vadstena 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 buildings standing on the shore of lake Vettern, three broad shafts of the inner courtyard, a moat and four circular cannon turrets. The original ramparts were demolished in the 19th century, these ramparts were discovered only in 1999, and the original stone buildings currently form the first floor of the castle. Castle in Vadstena well preserved and today is one of the best examples of Swedish architecture of the Renaissance.

The restructuring of the fortress into a Renaissance castle began in 1550-ies, when the Prince Magnus became the Duke of the province of Ostergotland. Duke Magnus suffered from mental illness and was the only son of Gustavus I. 22 August 1552 king Gustav I was married a third time to Catherine Stenbock in the castle of Vadstena. An interesting fact that one of the Banquet halls of the castle Wedding is called, although its construction was not finished for the wedding. Magnus died in 1595 and was buried in the Church adjacent to the castle of Abbey. The building was finished in 1620. Until 1716, he was a Royal Palace, but then the monarchs have lost interest in him, and it was used as a barn for storing grain.

Since 1899, the castle began to gradually turn it into a Museum. Today, visitors can see the historical exhibits on the first floor of the castle, to attend one of four cannon towers, second floor (it is closed in summer) and the third floor, furniture and paintings from the 16th and 17th centuries. In addition to the Museum in the castle also houses a tourist information center, office of international Academy of Vadstena and the archives of the County.