The Scaliger Castle at Sirmione is one of the few fortresses in Europe whose curtain walls stand directly in the lake, and its harbour was built not for trade but for warships. Construction began under the della Scala lords of Verona in the mid-thirteenth century, most likely during the rule of Mastino I. The fortress guarded the narrow neck of the Sirmione peninsula, the only land approach to a spit that runs four kilometres into Lake Garda. Verona and Garda were a single political system then. That old dependency is what modern day tours from verona to lake garda still trace, following the same corridor east of the Mincio that medieval garrisons once patrolled. The peninsula was inhabited long before the Scaligeri arrived. At its northern tip lie the Grotte di Catullo, the ruins of a vast Roman villa of the first century, built over three terraced levels and once faced in marble. The poet Catullus, born in Verona, called Sirmione the jewel of islands and peninsulas in a surviving lyric. Whether the villa was his family's is unproven. The name persisted regardless, and archaeologists have documented the olive groves that still grow over the foundations. The castle passed to Venice in 1405 and served the Republic as a naval station until the fortifications lost their purpose. The dock, enclosed by crenellated walls and reached under a drawbridge, remains the most complete example of a fortified lake harbour in Italy. Merlons follow the swallowtail Ghibelline pattern that marks Scaligeri work across the province, the same silhouette visible on Verona's Castelvecchio and Ponte Scaligero. Today the site is administered by the Lombardy directorate of the Ministry of Culture, and standard adult entry costs 10 EUR. The keep is reached by 146 steps, a climb that opens onto the sulphurous springs at Boiola, the church of San Pietro in Mavino, and the long shoreline running north toward Salò. Descriptive listings sold as a Sirmione Lake Garda day trip, or as skip-the-line Scaliger Castle admission, are all versions of the same short journey between two Scaligeri strongholds. What distinguishes the better day tours from verona to lake garda tours is that they treat Sirmione as a continuation of Verona rather than an escape from it, which is precisely what the stonework records. The lake ends the road; the castle ends the peninsula.