Take a guided excursion to St.Isaac's Cathedral, formerly main and largest Russian Orthodox cathedral built in St. Petersburg in 1858 by the architect Montferrand, is the fourth highest among the world's cathedrals under the single cupolas.It follows St Peter's in Rome, St. Paul's in London and Santa Maria del Fiorre in Florence. The richly-adorned interior, lined with marble, and with malachite and lazurite columns, was intended for up to 10 000 worshippers. Standing on the broad Isaac`s Square, its golden dome can be seen all over the city. On a clear day, the observation platform at the foot of the dome commands a fine view over St. Petersburg and its surroundings. Thereafter you proceed to The Comprehensive City Tour - when you see all the famous sights of Saint-Petersburg.