There are many different cannons in the Coastal Cannon Museum, all of which are used for defense. It is worth visiting.
The city has also been baptized by war, like the described cannon museum, which allows me to see the remains of history
Very characteristic museum with cannons for defence of different ages, many exhibits, worth visiting.
An attraction on Suomenlinna in Helsinki is mainly to show the historical relics of Suomenlinna as a maritime military fortress, and you can learn about the history of ancient Finland.