When Cosimo de'Medici, Grand Duke of Florence, addressed his commute to work in Palazzo della Signoria (Palazzo Vecchio) from his home one mile away in the Palazzo Pitti, he worried about the dangerous, dark trek he had to endure. Because the Medici already had assassination attempts, his architect, Giorgio Vasari, designed the elevated skyway so he could travel back and forth without being seen. The corridor became known as the Vasari Corridor and is now a gallery of self-portraits from Renaissance era to present day. Access is only available for groups of 15 or more and booking is a must. Admission: EUR 28.50.