St. Isaac's Cathedral (the official name is the Cathedral of St. Isaac the Dalmatian) is the largest Orthodox church in St. Petersburg. It is located on Isaakievskaya square. It has the status of a museum. Registered in June 1991, the church community received the opportunity to perform divine services in the cathedral. Today, services at the St. Isaac's Cathedral are held daily, except Wednesday. Sanctified in the name of St. Isaac of Dalmatia, revered by Peter I the saint, as the emperor was born on the day of his memory - May 30, according to the Julian calendar. Museum complex "State Museum-monument" St. Isaac's Cathedral. "

Built in 1818-1858 by the architect Auguste Montferrand; The construction was supervised by Emperor Nicholas I, the chairman of the construction commission was Karl Opperman. On May 30 (June 11), 1858, the new cathedral was solemnly consecrated by Metropolitan Grigory (Postnikov) of Novgorod, St. Petersburg, Estland and Finland.

The creation of Montferran is the fourth temple in honor of Isaac of Dalmatia, built in St. Petersburg.