Stand well back for this one as it is the largest Gothic Cathedral in the world and the third biggest in Europe. The overall design became the inspiration for the local sweet treat panettone . The construction took a staggering 500 years to complete, from 1386-1812 but when you see the 135 spires and 3200 sculptures you may understand why. The pigeon population in the square is almost equal to that of Piazza San Marco and beware the tricky birdseed sellers. The Cathedral is also said to be the home of an original nail from the cross of Christ, positioned high above the altar and brought down for public display in September. There's no bell tower to climb here but you can ascend the 165 steps to the roof to look out over the capital of style. Entrance to roof- lift €6, stairs €4.