Catacombs of Commodilla, on the Via Ostiensis, contain one of the earliest images of a bearded Christ. They originally held the relics of Saints Felix and Adauctus. The hypogeum leading to the catacombs was built in the fourth century. The catacombs were used for burials until the sixth century. Later, as happened to other Christian underground cemeteries, it was transformed into a place of worship of martyrdom: restoration of the basilica underground were made by several popes until the ninth century, a sign that the catacombs were still at that time a place of pilgrimage of devout Christians.
There were also found coins bearing the effigy of Pope Gregory IV (827-844) Pope Leo IV (847-855) finally gave the relics of the martyrs Felix and Adautto the wife of Emperor Lothair. Following the catacombs were abandoned and fell into oblivion. It was discovered in 1595 by archaeologist Antonio Bosio, but the first to identify it as that of Commodilla was in the nineteenth century, Giovanni Battista de Rossi. Restoration campaigns were performed at the beginning of the twentieth century and led to the complete excavation of the second level cemetery.
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.