Baldenstein Castle was the family castle for the Knights of Baldenstein, the first of which was mentioned in 1246. The central tower which now forms part of the castle was built around the same time. Very little is recorded about the Baldenstein family and by 1289 the castle was owned by the Freiherr von Löwenstein. Before 1289 he lost the castle in a war with the Freiherr von Rhäzüns, but in the peace treaty of that year received it back after giving Schwarzenstein Castle to Rhäzüns. In 1349 it passed to the Übercastel family. Wilhelm von Übercastel planned to expand and strengthen the castle, but was prevented by the Bishop of Chur, until he granted the Bishop certain rights. Originally the castle consisted of a rectangular bergfried. During the Late Middle Ages an administrative and residential wing was added to the west.
Around 1400 the castle passed to the Freiherr von Stein. Through marriage it then passed to the von Ringg (later Ringg von Baldenstein) family in 1453. In 1562 Luzius Ringg sold the castle to Jakob Ruinelli. The Ruinelli family lived in the castle for several generations. Jakob's grandson, also named Jakob, accompanied Jürg Jenatsch to Rietberg Castle in 1621 to murder Pompeius Planta during the Bündner Wirren. He, in turn, was stabbed to death in 1627 in a brawl between drunken officers. After his death the castle was inherited by the Rosenroll family. During the 16th and 17th centuries the castle was further expanded with a new, larger wing replacing the medieval residential wing. During the same time, the medieval ring wall was replaced with a new crenelated wall.
In 1738 the castle was acquired by the Salis-Sils family, who owned it for almost half a century. In 1782 it was inherited by Francesco Conrado, from Chiavenna in Italy. Francesco became a member of Senate of the Helvetic Republic after the French invasion of Switzerland in 1798. Eventually his descendants changed their name to Conrad and still own the castle. In 1877 the residential wing was mostly destroyed in a fire. It was rebuilt to its present appearance in the following years.
Sirmione castle was built near the end of the 12th century as part of a defensive network surrounding Verona. The castle was maintained and extended first as part of the Veronese protection against their rivals in Milan and later under the control of the Venetian inland empire. The massive fortress is totally surrounded by water and has an inner porch which houses a Roman and Medieval lapidary. From the drawbridge, a staircase leads to the walkways above the walls, providing a marvellous view of the harbour that once sheltered the Scaliger fleet. The doors were fitted with a variety of locking systems, including a drawbridge for horses, carriages and pedestrians, a metal grate and, more recently, double hinged doors. Venice conquered Sirmione in 1405, immediately adopting provisions to render the fortress even more secure, fortifying its outer walls and widening the harbour.
Thanks to its strategical geographical location as a border outpost, Sirmione became a crucial defence and control garrison for the ruling nobles, retaining this function until the 16th century, when its role was taken up by Peschiera del Garda.