St Isaac's Cathedral is among the most impressive cathedrals in Russia dominating in St. Petersburg's skyline for over 150 years. It is a functioning Orthodox Christian church which also houses a museum dedicated to its history in upper levels.
The first small wooden church was built in 1706 on the order of Peter the Great in honor of his patron saint Isaac of Dalmatia on the spot where now stands the statue of Tsar Nicholas I. Peter and Catherine's wedding was held in the little church, but then decided to replace it with a new “Petrine Baroque” stone building that look much like the church in the Peter and Paul Fortress.
The construction of the St. Isaac's Cathedral was finished in 1727 after Peter the Great's death, yet it was significantly damaged as it was built on marsh land.
The cathedral was reconstructed a few times, first by Catherine II the Great together with architect Antonio Rinaldi who rebuilt the stone beauty. Then by her son Paul in 1802, and finally the building of St. Isaac's Cathedral standing today was designed by Spanish engineer Augustin de Betancourt on the order of Tsar Alexander I.
They added the grand dome plated with gold to the Neoclassical cathedral, 10000 logs were placed in the cathedral's foundation to improve the marshy ground, 882 pounds of gold, 16 tons of malachite, and a 1000 tons of bronze were used for its interior, with the best masters working on the 7108 square yards of the mosaics in St. Isaac's.
The mighty St. Isaac's Cathedral can hold up to 14000 people, amazing with its sizes and beauty.