St. Isaac's Cathedral is the biggest Orthodox church of the northern capital and it is the fourth by size in the world. Its height is 101,5 m. Inside there can be up to 12 thousand people situated on 4000 square meters at the same time.
Peter I was born on May 30 on the day of Saint Isaak of Dalmatia – the Byzantine monk lived in the 4th century. The first small wooden church called in honor of Isaak of Dalmatia was built at the place of the present Admiralty where Peter I and Ekaterina's wedding took place. The second church was constructed on the bank of the Neva where the Bronze Horseman is situated nowadays. Shortly after that it was demolished. The third church was constructed on a place of the present cathedral, but it was too small and unsightly for the big growing city. So a competition for the best project of a new cathedral was announced. The French architect Montferrand won it.
100 kg of pure gold was spent for gilding of a dome. Even after more than 150 years without restoration the dome shines even at rainy weather.