Johansslocratickula

Stone Joannovsky ravelin was built from 1731 to 1740 according to the project of the military engineer B. K. Minih on the site of the first wooden ravelin of Peter and Paul Fortress, built on the eastern tip of the Rabbit Island in 1704-1705. Inside the walls were casemates-quarters, and on the left face - Joannovskie gates, which were joined by barrack rooms-cordegarde. On both sides of the ravelin were connected with it semiflanks half-counterguard. From Petrovskaya curtain ravelin was separated by a wide ditch, filled with water (dug up in 1891). Today the existence of the ditch is reminiscent of partially preserved boats - protective dams with small turrets - tongars and fences - palisades, which separated the ditch from the Neva and Kronverksky channel. In 1787, according to the project of the engineer R. R. Tomilov, the Nevsky facade of the southern half-counterguard Joannovsky ravelin was clad with granite slabs.

In 1894, the northern half-counterguard was rebuilt, where according to the project of the military engineer V. F. Asmuss built a one-story building for the undisturbed reserve of the Izhorsky reserve battalion. In the 1930s, in this building was the first domestic design bureau for the development of rocket engines - the Gas Dynamics Laboratory (GDL) (from 1973 - the Museum of Spaceflight and Rocket Technology named after V. P. Glushko).

In 1909, according to the project of the engineer S. A. Chistogradov in the southern part of the ravelin was erected a residential building for officers of the Leib-Gardesy Sniper Battalion. Now, this is the restaurant 'Asteria'.

In April-May 2008, repairs were carried out in the fortress. Work on Joannovsky ravelin affected the spit and the apron.

Sources:

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

https://www.spbmuseum.ru/themuseum/museum_complex/peterpaul_fortress/objects_fortress/ioanovski_ravelin.php