St. Isaac’s Cathedral is the largest Orthodox basilica in St. Petersburg, built between 1818 and 1858 by French-born architect Auguste Montferrand and named for St. Isaac of Dalmatia, patron saint of Peter the Great. Converted from a working church into a museum in 1931, the cathedral can hold up to 12,000 people beneath its soaring 101.5-meter dome.
The interior blends late classicism with Byzantine and neo-Renaissance touches, decorated with semi-precious stones gathered from across Russia along with mosaics and paintings by leading 19th-century Russian artists. A separate ticket allows visitors to climb roughly 260 steps to the 43-meter colonnade, which offers one of the best panoramic views over the city’s rooftops and canals.
Most visitors spend 1 to 2 hours between the cathedral museum and the colonnade climb. The museum is open daily 10:30am to 6pm (closed Wednesdays), and from May through September the colonnade also opens for evening viewing from 6pm to 9:30pm during the White Nights.
