Suomenlinna sea fortress was built on an island group outside Helsinki in the 18th century to protect Swedish-held Finland from a Russian attack. Today much of the fort is open to the public and is a popular day-trip from Helsinki. Besides the extensive fort ruins to explore, the island also is a prime viewing location to watch the big Baltic ferries that dock in Helsinki Harbour make their way through the narrow 400-ft (120m) channel between Suomenlinna and Vallisaari.

Following lunch in Helsinki’s Market Square, we took a ferry to Suomenlinna and spent a great afternoon exploring the old fort and watching the ferries run through the channel.

Below are trip highlights from May 19, 2019 at Suomenlinna, Finland. Click any image for a larger view, or click the position to view the location on a map. And a live map of our current route and most recent log entries always is available at mvdirona.com/maps.

Market Square Position: 60°10.05’N, 24°57.24’E A tasty grilled salmon lunch at one of the food stalls in Helsinki’s Market Square.

Allas Sea Pool Position: 60°9.99’N, 24°57.36’E Allas Sea Pool viewed from the ferry from Helsinki to Suomenlinna sea fortress.

Merisotakoulu Position: 60°8.98’N, 24°58.82’E The Merisotakoulu (Finnish Naval Academy) operates from this building and others on the island of Pikku Mustasaari at Suomenlinna.

Bunker Position: 60°8.88’N, 24°58.74’E Bunker, possibly for munitions storage, on a small island connected to Lansi-Mustasaari.

Lansi-Mustasaari Position: 60°8.89’N, 24°58.41’E Looking north across the fortifications on the tip of Lansi-Mustasaari.

Helsinki Harbour Position: 60°8.89’N, 24°58.41’E Helsinki Harbour viewed from Lansi-Mustasaari, Suomenlinna. The 666ft (202m) ferry Silja Symphony is on the left and the cathedral Tuomiokirkko is prominent at center.

West Harbour Position: 60°8.89’N, 24°58.41’E View from Lansi-Mustasaari in Suomenlinna to West Harbour, where we took our ferry to Tallinn.

Suomenlinna Church Position: 60°8.88’N, 24°59.14’E Suomenlinna Church was built as a Russian Orthodox garrison church in 1854 when Russia controlled Finland and now is Lutheran. We particularly liked the fence around it, made from sets of three cannons and a massive ship’s chain.

Suomenlinna Church Interior Position: 60°8.87’N, 24°59.17’E The elegant interior of Suomenlinna Church.

Sea Fortress Suomenlinna Position: 60°8.70’N, 24°59.27’E Photograph at Suomenlinna Museum showing the entirety of Sea Fortress Suomenlinna. Our ferry landed at the north end, near where the steeple of Suomenlinna Church is visible.

Winter Position: 60°8.71’N, 24°59.27’E Sea Fortress Suomenlinna in the winter. Note the paths through the ice between Helsinki and the island complex. Several hundred people live here year-round and rely on the ferry service to get on and off the island.

Vesikko Position: 60°8.55’N, 24°59.35’E The Finnish submarine Vesikko on display at Suomenlinna. The 134ft (41m) vessel was built in the 1930s and carried a crew of 20 and is the only surviving Finnish submarine from World War II. The Paris Peace Treaty of 1947 classified Finland as an ally of Nazi Germany and the country was not allowed to have submarines. All except the Vesikko were scrapped.

Tunnel Position: 60°8.57’N, 24°59.29’E Most of Suomenlinna fortress is open to the public, including many underground tunnels and caverns.

Walls Position: 60°8.61’N, 24°59.23’E A path leading between the outer fortress wall on the right and inner fortifications on the left.

Thickness Position: 60°8.67’N, 24°59.15’E With its heavy fortifications and extremely thick walls, Suomenlinna Fortress was considered near-impregnable and referred to as the “Gibraltar of the North”.

Arches Position: 60°8.67’N, 24°59.15’E A series of beautiful stone arches connecting rooms in a building at Suomenlinna Fortress.

Augustin Ehrensvard Position: 60°8.66’N, 24°59.12’E Memorial in the Great Courtyard to Augustin Ehrensvard, the architect of Suomenlinna Fortress.

Viapori dock Position: 60°8.68’N, 24°59.08’E Viapori dock, built at Suomenlinna in the mid-18th century, is one of the oldest operational dry docks in Europe and one of the largest in the world when it was completed. To get an idea of the size of the dock, a large tugboat is in the center of the picture and two 100ft+ sailing yachts are on the right, and still the dock looks near empty.

Cafe Piper Position: 60°8.51’N, 24°59.09’E Having a break with a view at Cafe Piper.

Kustaanmiekka Position: 60°8.42’N, 24°59.07’E Russian-era fortifications at Kustaanmiekka along the southwest coast of Suomenlinna Fortress.

Cannon Position: 60°8.36’N, 24°59.09’E This Russian cannon had a real steampunk look to it.

Underground Position: 60°8.33’N, 24°59.43’E Walking through underground tunnels in Kustaanmiekka.

Silja Symphony Position: 60°8.30’N, 24°59.45’E Starting around 5:15pm, the big Baltic ferries that dock in Helsinki Harbour make their way through the narrow 400-ft (120m) channel between Suomenlinna and Vallisaari. We found a spot just outside the fortress wall to watch them pass. This is the 666ft (202m) ferry Silja Symphony exiting to sea.

Mairella Position: 60°8.31’N, 24°59.45’E Jennifer waving to the passengers on the 576ft (174m) ferry Mairella as it passes between Suomenlinna and Vallisaari. The ferries run at a good 12kts through the narrows—it looks crazy.

Ferries Position: 60°8.33’N, 24°59.40’E We’re amazed at the number of ferries that operate in the Baltic. The three in sight run from Helsinki Harbour and several more run from West Harbour.

Viking XPRS Position: 60°8.31’N, 24°59.38’E The 606-ft (185m), 2,500-passenger, 240-car ferry Viking XPRS returning from Tallin. We watched this one go through the narrows from a viewpoint above the fortress walls. We’re standing at about the same height as the bridge of the Viking XPRS and you can see how large the ship is for that channel.

King’s Gate Quay Position: 60°8.40’N, 24°59.39’E King’s Gate Quay, the ceremonial entrance to Suomenlinna Fortress.

Valontuojia Position: 60°9.91’N, 24°56.93’E Valontuojia (Light Bringer) is a memorial in Kasarmitori square to those who died in Finland’s winter war with Russia from 1939-1940. Viewing holes in the sphere show archived photographs inside and perched atop is a representation of a Finnish solder. At night lights shine through the holes.

Evening Light Position: 60°9.89’N, 24°56.88’E The evening sun lighting up the pastel-colored Art Nouveau buildings along Kasarmitori square.

Juuri Position: 60°9.83’N, 24°56.77’E An excellent meal on the terrace at Juuri, who specialize in Sapas, Spanish Tapas with a Finnish twist.

Empty Position: 60°10.06’N, 24°57.28’E Walking back through a now-empty Market Square. All the vendors we’d seen earlier, including the one we had lunch at, are now gone. We wouldn’t have guessed such a large and busy market would be temporary.

Click the travel log icon on the left to see these locations on a map, with the complete log of our cruise. On the map page, clicking on a camera or text icon will display a picture and/or log entry for that location, and clicking on the smaller icons along the route will display latitude, longitude and other navigation data for that location. And a live map of our current route and most recent log entries always is available at mvdirona.com/maps.