Sea Fortress Suomenlinna, Helsinki

4.4
#1 of 1,713 in Things to do in Finland
Must see · World heritage site · Castle · Military Facility
Visit World Heritage Site Sea Fortress Suomenlinna to see a sea fortress built on a collection of six islands. This ruggedly beautiful spot is a favorite among both locals and tourists. The fortress was built in 1748 and inhabited by Swedes and Russians until 1918, when it became a part of independent Finland. View the impressive fortified structure, constructed by the Swedish crown to withstand attacks from 18th-century Russia (who eventually overtook the islands in 1808). Nowadays the site supports a town with civilian inhabitants and draws visitors from the mainland of Finland. For travelers who use our online itinerary creator, Helsinki holidays become easier to arrange, with trips to the Sea Fortress Suomenlinna and other attractions mapped out and timetabled.
Create an itinerary including Sea Fortress Suomenlinna
© OpenMapTiles © OpenStreetMap contributors

Sea Fortress Suomenlinna reviews

Rate this attraction
TripAdvisor traveler rating
TripAdvisor traveler rating 4.5
8,127 reviews
TripAdvisor
  • We visited the Suomenlinna Sea Fortress way out of season and that is the reason for my rating which, I am sure, would be far higher if we had seen the island either in summer, when a picnic and a...  more »
  • This is a must visit for any tourist to Helsinki: a nice brief ferry ride across the archipelago sea, and then a few hours spent exploring this lovely island with its historical walls and buildings...  more »

Plan your trip to Helsinki

  • Get a personalized plan

    A complete day by day itinerary
    based on your preferences
  • Customize it

    Refine your plan. We'll find the
    best routes and schedules
  • Book it

    Choose from the best hotels
    and activities. Up to 50% off
  • Manage it

    Everything in one place.
    Everyone on the same page.

Popular things to do in Helsinki

See all ›
4.2
Duration: 1h 30 min
4.3
Duration: 1h 30 min
4.3
Duration: 1h 30 min

Hidden gems in Helsinki

3.9
Duration: 8 hours
4.1
Duration: 1h 30 min
4.2
Duration: 1h 30 min

Side trips from Helsinki

4.7
Duration: 8 hours
5.0
Duration: 8 hours
4.5
Duration: 2 hours
5.0
Duration: 4 hours

Shopping in Helsinki

See all ›
4.2
Duration: 1h 30 min
3.4
Duration: 1h 30 min
5.0
Duration: 1h 30 min
4.2
Duration: 1h 30 min

Nearby attractions in Helsinki

3.7
Duration: 30 minutes
4.9
Duration: 2h 30 min
3.9
Duration: 1h 30 min
4.9
Duration: 1h 30 min
4.5
Duration: 2 hours
4.4
Duration: 2 hours
4.4
Duration: 2h 30 min
4.3
Duration: 30 minutes