Locals will almost certainly tell you that these romantic lakeside ruins were once the site of the villa of Catullus (87–54 BC), one of the greatest pleasure-seeking poets of all time. Present archaeological wisdom, however, does not concur, and there is some consensus that this was the site of two villas of slightly different periods, dating from about the 1st century AD. But never mind—the view through the cypresses and olive trees is lovely, and even if Catullus didn't have a villa here, he is closely associated with the area and undoubtedly did have a villa nearby. The ruins are at the top of the isthmus and are poorly signposted: walk through the historic center and past the various villas to the top of the spit; the entrance is on the right. Alternately, take one of the frequent tourist trains from town for €1 each way. A small museum offers a brief overview of the ruins (on the far wall).
Piazzale Orti Manara, Sirmione, Lombardy, 25019, Italy