Within almost all XVII century of coast of Neva belonged to Swedes. In October, 1702 Russian armies at sources of Neva have taken fortress Noteburg (Nutlet). Peter I has renamed it into Shlisselburg that means "key-city". The capture of this fortress became valid a key which should open a way to Baltic sea. The output to the sea became completely open, when the Swedish fortress Nienschanz located on right on May, 1st, 1703 capitulated protect Neva in a place of a confluence of it of the river of Okhta. The fortress has been renamed in Schlotburg – "fortress-lock". To be fixed on coast of Baltic sea, tsar Peter I has decided to construct a new fortress on island Enisaari (in translation from Finnish – «the Harel island»). The small island (600 meters at length and 360 meters at width) from different directions is protected by Neva which is divided here into two sleeves and to a channel, bending around island from the north. Owing to the open district, it was possible to conduct without handicapes artillery fire in all directions.
Works on a bookmark of a fortress under direction of the nearest assistant to tsar Alexander Danilovicha Menshikov (Peter I at this time was on Ladoga – the young Russian fleet there was under construction) have begun 16 (27 on new style) May, 1703. This day is considered day of the basis of St.-Petersburg. First the fortress was called Sanct-Piterburh – sacred Peter's Fortress. Later this name has been carried on a city under construction. Peter I has with own hand thought up the plan of a fortress. However, it is supposed, that the French engineer Zhozef Lamber assisted him with this. The fortress looked by way of as a wrong hexagon. On corners of a fortress bastions – strengthenings of the pentagonal form have been constructed. Bastions incorporated among themselves direct walls – Certains. Later two of them have in addition covered with ravelins – the auxiliary strengthenings of the triangular form consisting of two walls. Ravelins have been named Alexeevsky (in honour of father Peter I of tsar Alexey Mikhajlovich) and Ioannovsky (in honour of senior brother Peter I Ioann Alekseevich). The nearest assistants to tsar watched construction of bastions, therefore their names and have named bastions: Naryshkin, Trubetskoy, Zotov, Golovkin and Menshikov. The first, Tsar's bastion, was under construction under direction of Peter I. Civil work took place with the big haste – Swedes were close. The set the soldier, tens thousand «craft people» and masters has been involved. By the autumn earthen shaft on which have established more than hundreds instruments have been erected. In 1705 – 1708 on other side of channels have been built the Krownwerk – additional strengthening, under the form reminding a crown which should protect a fortress from the north, from a land. Today the Military-historical museum of artillery, engineering armies and armies of communication settles down there.
Because of constant threat of an attack of Swedes, Peter I makes a decision to replace earthen shaft of a fortress with powerful brick strengthenings. New walls of a fortress reached height in 9 meters and average width in 16 – 20 meters. Walls became double: space between them fell asleep sand, rubble or arranged there rooms – casemates. In casemates soldiers were placed or warehouses with an ammunition settled down. In the autumn of 1706 under direction of known architect Domeniko Trezini works on reorganization of a fortress have begun. About forty thousand piles it has been hammered under the basis of stone walls. At a fortress six gate. Front doors were the Peter gate executed in the form of a triumphal arch and located in Peter's certain between Tsars and Menshikov bastions. First they were wooden, but then Trezini has reconstructed them in a stone. After in 30th years of XVIII century have constructed Ioannovsky ravelin, the Peter gate became internal. In 1740 were Juseppe Trezini in a ravelin a new gate – Ioannovsky, reminding Peter, but less elegant and solemn have been erected.
From Neva there is the Neva gate reconstructed by architect N.A.Lvovym in 1787. Through them it is possible to get on Commandant's quay. In territory of the Peter and Paul Fortress various constructions have been constructed: warehouses of provisions, artillery zaichgaus (a warehouse of the weapon), the Commandant's house (with an apartment of the commandant of a fortress and office), a guardroom (guard house), the Engineering house. During reign of empress Ekaterina II works on facing by a granite of the fortifications turned to Neva have begun. Besides on bastions of a fortress have arranged granite turrets for hour. Now every day it is equal at 12 o'clock in St.-Petersburg the gun shot which is made from Naryshkin of a bastion of the Peter and Paul Fortress is distributed. This tradition goes back to 1735 when in the Academy of sciences of St.-Petersburg Z.N.Delilya's project was discussed. It was offered, daily at midday, on a signal of an observatory to shoot a single charge from a gun of a bastion of Admiralty. This project has been rejected, however later forty two years from a gun all the same have started to shoot to warn city dwellers about rising of water in Neva. In 20th years of XIX century this tradition has been broken: bastions have disassembled, and the gun has broken off. On February, 6th, 1865 the gun has again started to shoot from a court yard of Admiralty, and then from Naryshkin of a bastion that city dwellers find out about approach of midday, and also it warned of threat of flooding. In 1934 midday shots have stopped, but in 1957, on the eve of celebrating the 250 anniversary of city, the ancient tradition has been revived.