During the capture of Vyborg by the troops of Peter I in 1710, the city's defensive structures suffered serious damage, and the medieval castle, as a means of defense, became completely obsolete. The need to build modern fortifications to protect from the northwest—the most likely direction of the Swedish troops' advance—was realized during Peter I's lifetime.

In January 1724, the preparation of fortification projects for the Vyborg fortress was entrusted to the most prominent military engineers of that time: Lieutenant General Minikh, Major General Coulon, and Engineer Colonel De Brigni. To this day, only the drawings of Minikh and Coulon have survived. Both projects proposed strengthening the coastal area of Tverdysh Island to the northwest of the castle. Minikh's project suggested constructing a fortified strip crossing the entire island. According to Coulon's project, the defensive belt covered only the coastline of the island opposite the castle in a semicircle and continued along the cape now called Smolyanoy Bereg (Tar Coast). The projects submitted to the Military Collegium in 1728 were reviewed for several years. As a result, Minikh's project, which required a large number of weapons and a significant garrison, was deemed excessively expensive, and in 1731 Coulon's economical and less labor-intensive plan was approved, which also provided less vulnerable rounded flanks of the fortifications. He proposed placing the fortified strip in a semicircle along the coast of Tverdysh Island, capturing Smolyanoy Bereg and Protective Bay. Thus, the Vyborg castle and most of the city were placed under protection. The construction of the complex was entrusted to Lieutenant General Minikh. By the beginning of 1740, under his supervision, 2 bastions, a moat, and the main buildings were completed. The Russo-Swedish War of 1741–1743 required strengthening the defensive structures and accelerated the work. The project was prepared by Lieutenant General Johann Luberass, who also supervised the construction. In the early 1750s, Abram Hannibal, Pushkin's great-grandfather, participated in the works on the Anninsky fortifications. In 1772 and 1808, the fortifications were repaired due to renewed tensions in Russo-Swedish relations. After the peace agreement between Russia and Sweden (1809), the border zone moved significantly away from Vyborg. The Anninsky fortifications never faced an enemy, and their improvement continued until 1854—in connection with the Crimean War. In 1864–1865, the fortifications were bisected into two parts by a road (Ostrovnaya Street), which caused them to lose their defensive significance entirely.

Why such an interesting name—the Crown of Saint Anna (we have already clarified the Anna part earlier). When you look at the Anninsky fortifications on a map, it becomes clear. From a bird's-eye view, the fortifications resemble precisely this symbol of power. The core of the fortification complex consists of 3 ravelins—Central, Eastern, and Western. Between them are 4 bastions connected by curtains. A complex of defensive moats, ramparts, and lunettes completes the image of a crown. For its time, the Anninsky fortifications in Vyborg were an impregnable fortress, built according to the latest advances in fortification art. The outer walls of the fortifications are 10 meters high, 3 meters thick, faced with granite, and additionally reinforced with a counterscarp. The slopes of the ramparts are also strengthened with smooth granite boulders bonded with a special mortar.

From east to west, the Anninsky fortifications are crossed by the old royal road. Its original cobblestone paving has been preserved to this day. Now this road, passing through the Central ravelin, is called Petrovskaya Street. It leads straight to Monrepo Park. The safety of passages from the city side was ensured by the Ravelin Gate, and from the west by the Friedrichshamn Gate. Due to the construction of an additional road, two more gates were built—the Abos Gate (leading to Turku) and the Hiekka Gate.

Within the fortress, a house was built for the commandant, a special room for the guard service (cordegardia). For the soldiers, 3 huge barracks were erected by the standards of that time. The officer corps was housed in separate apartments divided into 2 quarters. These buildings have survived to this day.

At a safe distance from the residential buildings were storage facilities for provisions, weapons, and gunpowder.

The central (Petrovskaya) square of the complex is decorated by a house built in 1847. General Mendt, who commanded the garrison, lived there. Later, near it, the Engineering House and another residential building for employees of the relevant services and leaders of Annenkron were built. In 1996—the 300th anniversary of the Russian Navy—a monument was solemnly laid on Petrovskaya Square, and an anchor from a ship of Peter I's era was installed.

As a historically significant place, the Anninsky fortifications boast monuments within the fortress. Most of them are located in Petrovsky Park. The first and most impressive is the memorial to General Admiral Apraksin of the Russian army, who commanded the Russian troops in the Northern War. It was his soldiers who took Vyborg in 1710. The monument to the military leader is located in front of the Fortress Bridge. The next in historical significance is the monument to Peter I. It is located at the highest point of the Tervaniemi cape. The monument was destroyed by the Finns when Finland gained independence from the Russian state. The statue itself escaped this fate and returned to its place after the Soviet-Finnish war. The misfortunes of the bronze Peter I did not end there. In August 1941, it was damaged again, and in 1954 the statue and pedestal were finally restored. On the territory of the Central ravelin, there is a memorial to the Russian soldiers who died during the capture of Vyborg. Its first unveiling took place in 1910, on the 200th anniversary of the memorable date. Later, the monument was demolished by the Finns. It was restored by the end of the 20th century. Just behind the Friedrichshamn Gate, there is a grim site—the place where 200 peaceful Vyborg residents were shot by Finnish rangers. A small new granite monument testifies to this. Previously, a large cross stood there. Candles are always lit on the monument's pedestal. Walking around the Anninsky fortifications, one can see mass graves lined with granite stones. The residents of Vyborg cherish their roots and history. The territory of Annenkron is always clean and tidy.

It is clear that now the fortress no longer has defensive significance. Everything is gradually deteriorating, and the buildings require restoration. Currently, the restoration of the cordegardia of the Anninsky fortifications, located near the Friedrichshamn Gate, is necessary. A severe fire spared no mercy on the historic building. The preserved powder magazine now houses a restaurant and a Chocolate Museum. People still live in the officer houses. The soldiers' barracks have also been divided into apartments.

Currently, the city authorities lease the fortification territory. For example, to the left of the Central ravelin, between the bastions, there is a karting track. And near the Apraksin monument, there is a rope park.

Now, on Ostrovnaya Street within Annenkron, there is the fund of the District State Archive of the Leningrad Region. In the far part of Petrovskaya Embankment, a beach is equipped for guests and residents of the complex. Not far from it operates the café "By the Fortress." In summer, the ancient fortifications are popular with the Historical Reconstruction Society. Every year, for several days, the fortress comes alive. The colorful knightly tournament leaves no one indifferent.

Sources:

https://ru.wikipedia.org/wiki/Anninsky_fortifications

https://rekvizit.info/blogs/annenskie-ukrepleniya/