The historical centre of Sirmione is pedestrianised; its narrow winding lanes busy with tourists. Orienting yourself can be confusing, but the town is so small that you can't get lost for long. Sirmione is picturesque throughout, but its two main tourist attractions are the castle and the Roman ruins. A panoramic walk (signposted) leads out around the the promontory, and on a clear day you can enjoy great views over the lake and towards the mountains in the north.
What can you see?
Rocca Scaligera - Scaliger Castle
This fortification, surrounded by water, was built near the end of the 12th century as part of a defensive network surrounding Verona. Although the struggles between the Ghibellines and Guelphs featured largely in the history, the original military adventure onto the peninsula was to wipe out the population of Sirmione, who were heretic Cathars and 2,000 of whom were subsequently burned at the stake in the Arena in 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. After another fortification was built at nearby Peschiera, the castle lost its importance and was used as a storage depot. It was taken into government ownership at the start of the 20th century.
Grotto of Catullus - The "Grotto of Catullus" on the end of the Sirmione peninsula is a bit of a misnomer as it is neither a grotto nor - contrary to what some tourist blurbs would have you believe - did the Roman poet Catullus ever live there. It was originally termed a "grotto" in reference to the run-down and collapsed walls. As far as the history goes, Catullus lived before this building ever existed (although his family did own a villa here). The villa itself is a three-story building from around 150AD (Catullus died in 54BC) and the main sights to be seen are the supports for what was once a patrician villa for a rich family. There is a small museum at the entrance and the site can be visited. As an important strategic point, Sirmione was continually engulfed in the turbulent history of northern Italy, whether it was through the waves of invasions following the fall of the Roman Empire, the expansion of the Lombards, or the intricate struggles between the Guelphs and the Ghibellines in the Middle Ages (essentially between a political grouping supporting the Pope and one supporting the Emperor).