Naples, city below a volcano
Inside the Duomo di Napoli, (Cattedrale di Santa Maria Assunta or Cattedrale di San Gennaro, after Naples' patron saint), the city's grand Gothic cathedral. It was commissioned by King Charles I of Anjou in 1294 and completed in the early 14th century. The church houses a vial which is supposed to hold the coagulated blood of the saint, which is brought out twice a year. The “blood” then usually liquefies; if this doesn't happen, then legend has it that disaster will befall Naples.