That same year, work also began on the Peter-Paul Cathedral inside the fortress of the same name. Its towering steeple is a city landmark.

For example, there is Kazan Cathedral, with its semicircular shape and frontal colonnade. Its striking appearance on the city’s foremost street, Nevsky Prospekt, played a role in the street’s being called one of the world’s great thoroughfares. Later, construction began on St. Isaac’s Cathedral. Some 24,000 piles were driven into the underlying marshy ground to support the structure, and 220 pounds [100 kg] of pure gold were used to gild its massive cupola.