Stroll past landmarks and through tunnels before settling in for a lunch of pizza, a classic dish first created in Naples. You will see the imposing 13th-century Castle Nuovo on the way to Piazza Plebiscito, the city’s largest pedestrian square. Four Bourbon royal residences overlook the piazza, including pink-hued Palazzo Reale. During free time, you might browse the shops or simply relax while taking in the sights. Naples also features a stunning attraction below the surface—the Bourbon Tunnel. Begun in 1853 as an escape route for royalty, the cavernous tunnel was never finished and became part of an aqueduct system. As you will discover while in the depths of the tunnel, it was also used as an air raid shelter during World War II. Returning to the surface, you will stop for a lunch of Pizza Margherita. It is a fitting choice, as the dish was supposedly invented in Naples to honor the visiting Queen Margherita of Savoy.