As you wander around, you'll notice that Mantua's squares are handsomely proportioned spaces surrounded by medieval and Renaissance churches and palazzi. The piazze open one into another, creating the wonderful illusion that walkers in the city are strolling through a series of opera sets.
The southernmost of these squares, and the place to begin your explorations, is Piazza delle Erbe (Square of the Herbs), so named for the produce-and-food market that transpires in stalls to one side. Mantua's civic might is clustered here in a series of late-medieval and early Renaissance structures that include the Palazzo della Ragione (Courts of Justice) and Palazzo del Podestà (Mayor's Palace), from the 12th and 13th centuries, and the Torre dell'Orologio, topped with a 14th-century astrological clock. Also on this square is Mantua's earliest religious structure, the Rotunda di San Lorenzo, a miniature round church from the 11th century (summer daily 10am-noon and 2:30-4:30pm, winter daily 11am-noon, though hours may vary; free admission). The city's Renaissance masterpiece, Sant'Andrea Basilica, is off to one side on Piazza Mantegna.
In the adjoining Piazza Broletto (just north as you work your way through the Old City), the statue of Virgil commemorates the poet who was born near here in 70 B.C. and celebrated Mantua's river Mincio in his Bucolics. The next square, Piazza Sordello, is huge, rectangular, and somberly medieval, lined with crenelated palazzi. Most notably, though, the massive hulk of the Palazzo Ducale forms one wall of the piazza. To enjoy Mantua's soulful lakeside vistas, follow Via Accademia through Piazza Arche and the Lungolago Gonzaga.