Explore central Venice and Piazza San Marco on a guided walking tour. Find out why this is the most important square of the city, and why it was the political center of the Venetian empire.  See sights such as the Campo Santa Maria Formosa, Marco Polo's House, Rialto Bridge and markets,  San Giacometto Church, Basilica di San Giovanni e Paolo —  "the Venetian Pantheon" — and the famous “Mercerie” shopping street. See Doges’ Palace, the former residence of the Doge in Piazza San Marco, where the Venetians did business or organized the famous crusades. Then, see the breathtaking Golden Basilica with the famous horses carried from Constantinople, a symbol of the cultural influence from the Byzantine and Roman empires. Cross the arcade under Napoleon's Palace, built by the emperor to enjoy a modern Ballroom and to admire the Royal Garden that was built for Sissi, the Austrian Empress. Next, admire the astronomic tower and the Renaissance clock that overlook the square. Finally, see the famous Bridge of Sighs and the Prison Palace, from where only Casanova managed to escape.