The Neva Gate of the Peter and Paul Fortress and the adjacent pier were added to the south wall much later than the original structure, when it had lost its strategic military significance. The gate was designed by the architect Nikolai Lvov in 1787 in stern neo-Classical style.
Through this gate prisoners passed on the way to their executions elsewhere (usually - in the Schlisselburg fort up the Neva River). Several of the fortress's bastions, concentrated at its far western end, were put to use over the years mainly as political prisons. The first prisoner confined in its dungeons was Peter the Great's own son, Alexei, who was tortured to death in 1718 for treason, allegedly under the tsar's supervision. The prison was enlarged in 1872, when an adjacent one, Alexeivsky Bastion, which held such famous figures as the writers Fyodor Dostoyevsky and Nikolai Chernyshevsky, became overcrowded with dissidents opposed to the tsarist regime. A partial chronology of revolutionaries held here includes some of the People's Will terrorists, who killed Alexander II in 1881 (my great-grandfather, who had taken part in this assassination, too); Lenin's elder brother Alexander, who attempted to murder Alexander III (and was executed for his role in the plot); and Leon Trotsky and Maxim Gorky, after taking part in the 1905 revolution. The Bolsheviks themselves imprisoned people here for a short period, starting with the members of the Provisional Government who were arrested and "detained for their own safety" for a few days, as well as sailors who mutinied against the Communist regime in Kronstadt in 1921. They were apparently the last to be held here, and in 1925 a memorial museum (to the prerevolutionary prisoners) was opened instead.
When you walk through the arch of the Neva gate, you’ll note various plaques on the inside walls showing the water levels of some of the city's severest floods. You can imagine the degree of disasters which sometimes fell upon the city.