This cathedral, which was modelled on St. Peter's in Rome, is one of the city's most majestic. It was built from 1801 to 1811 to house the miracle-working Icon Our Lady of Kazan. The dome is 80-metres high and the colonnade facing Nevsky has 96 columns. Be warned, it's a quiet place and they don't like you to talk a lot in here, it's place of prayer and contemplation.