This large military museum sits in the crownwork outside the Peter and Paul Fortress, surrounded by its own moat. The collection ranges from early firearms and edged weapons to artillery, engineering equipment, communications gear, and missiles, so it works best for visitors with a real interest in military history.
The museum is a short walk from the fortress and pairs naturally with Petrograd Side sights. Labels are mostly in Russian, so non-Russian speakers may want to read up before visiting or focus on the scale and variety of the displays.