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The stone wall and ramparts of Kustaanmiekka in Suomenlinna in the evening light, with a small red and white lighthouse on the shore rocks and a sailing boat in the strait. Photo: © Helsinki Partners / Kari Ylitalo.

Photo: © Helsinki Partners / Kari Ylitalo.

Suomenlinna by boat – a World Heritage Site a short ride away

Suomenlinna is an 18th-century sea fortress off Helsinki and a UNESCO World Heritage Site. By boat, you arrive at Suomenlinna's only guest harbour, next to the dry dock, and from there you can walk to the ramparts, museums and cafés. The journey from Tervasaari is short, so Suomenlinna is also a good choice for a trip of just a few hours.

Details checked against sources in October 2026.

See rental boats on Friilo (opens in a new tab)See the route to Suomenlinna

Services on site

  • Guest jetty
  • Electricity
  • Drinking water
  • Toilet
  • Sauna
  • Restaurant
  • Café
  • Shop
  • Swimming beach
  • Laundry
  • Septic emptying
  • Waste disposal
  • No fuel

Many services are only open in the summer season, so check opening hours on the destination's website.

Why go to Suomenlinna?

The Swedish Crown began building the fortress in 1748 as a defence against Russia, and the work was led by Augustin Ehrensvärd. The fortress lies on eight islands, six of which are fortified. The fortress surrendered to the Russians in May 1808, and it was expanded during the period of Russian rule. During the Crimean War, in August 1855, an Anglo-French fleet bombarded the fortress. The name Viapori (Swedish: Sveaborg) was changed to Suomenlinna in 1918.

Suomenlinna was inscribed on the UNESCO World Heritage List in 1991. It is also a living district of the city, with about 800 residents and nearly a million visitors a year. The best-known sights include the King's Gate on Kustaanmiekka, which is the symbol of the fortress; the Ehrensvärd Museum in the former Commandant's House on the Great Courtyard; and the submarine Vesikko, launched in 1933 and the only surviving submarine of the Finnish Navy.

Next to the guest harbour is the dry dock, construction of which began in 1750. It is the oldest dry dock in Finland and one of the oldest in the world still in operation, and today wooden sailing ships are restored in its large basin.

Because the ride is short, you can make the trip in just an afternoon, and it is easy to spend the whole day walking and visiting museums and cafés.

Up-to-date information

Two children on a wooden walkway under the stone vaults of a fortress passage in Suomenlinna. Photo: © Helsinki Partners / Laura Dove.
Photo: © Helsinki Partners / Laura Dove.

Who is this trip for?

The trip suits people interested in history and groups who want to combine a short boat ride, a walk and a coffee break. Suomenlinna is also a good destination for a first boat trip off Helsinki, as the journey is short and the island has services all year round.

A visitor climbs stone steps up a grassy mound towards the ruins of an old fortification in Suomenlinna on a grey autumn day. Photo: © Helsinki Partners / Outi Neuvonen.
Photo: © Helsinki Partners / Outi Neuvonen.

Route to Suomenlinna

Departure point
Tervasaari departure harbour: information and travel times

Tervasaari → Suomenlinna

Distance / one way
4 nm
Travel time / one way
approx. 20 min
Fuel / one way
approx. 4 l
Fuel / round trip
approx. 8 l

Travel times are calculated at a cruising speed of 25 knots and include the slower sections of the route. The fuel estimate is based on a consumption of 0.9 l/nm. Actual consumption depends on the boat, the weather, load and driving style.

The route passes through the narrow Kustaanmiekka strait, which is also used by large passenger ships. Give them room and be prepared for the waves and currents they cause. There are speed limits off Helsinki, and in the Suomenlinna waters the speed limit is 10 km/h and creating wash is prohibited. The estimated travel time takes the speed limits into account. Also allow time to find a berth, as berths in the guest harbour cannot be booked in advance.

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Travel times are estimates without stops and depend on the conditions. The round-trip fuel estimate assumes you return the same way. Also allow time for the destination itself.

Wind forecast: Suomenlinna

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Back to the Suomenlinna route on the home page

Suggested plan for a day in Suomenlinna

This is a flexible idea for a self-guided day trip to Suomenlinna.

  1. 01

    Book a rental boat on Friilo and arrange the pick-up and refuelling with the boat's owner. Look at the route and the estimated travel time.

  2. 02

    Set off in good time, as the guest harbour's berths fill up on a first-come, first-served basis.

  3. 03

    Head through the Kustaanmiekka strait to the guest harbour and moor the boat according to the harbour's instructions.

  4. 04

    Walk past the dry dock's viewing platform to the Great Courtyard and the Ehrensvärd Museum, and continue to the ramparts of Kustaanmiekka and the King's Gate.

  5. 05

    Have a coffee or lunch break at one of the island's cafés or restaurants, for example, in the summer season, at the harbour bistro Valimo in the guest harbour.

  6. 06

    Start the return trip in good time, taking into account the weather and the boat's return time.

Map: Suomenlinna – paths and roads, the guest harbour, the museum, the café and the restaurant.
The map shows paths and roads, the guest harbour, the museum, the café and the restaurant. Map data © OpenStreetMap contributors (ODbL), dashed lines and harbour location based on our routes.
Old cannons under the trees in Suomenlinna in autumn, with yellow and orange leaves on the ground. Photo: © Helsinki Partners / Yiping Feng and Ling Ouyang.
Aerial view of the ramparts and stone walls of Suomenlinna in the evening light, with a path between the grass-covered ramparts and the open sea behind. Photo: © Helsinki Partners / Kari Ylitalo.
Photos: © Helsinki Partners / Yiping Feng and Ling Ouyang (cannons) and Kari Ylitalo (ramparts).

Guest harbour next to the dry dock

Suomenlinna's guest harbour is on Susisaari, at the edge of the dry dock, and you approach it along the fairway between Länsi-Mustasaari and Susisaari. The harbour has about 40 guest berths. Berths are taken in order of arrival, as advance bookings are not accepted. Fuel is not sold in Suomenlinna, so arrange refuelling with the boat's owner before you set off.

The guest harbour is the only place in Suomenlinna where visitors may moor their boats. The other jetties are used by the authorities, the Finnish Defence Forces, ferry and waterbus services or residents, and mooring at them is not allowed.

The guest harbour serves boaters from late spring until the end of September. The harbour's services are in the dockyard's old ammunition store, in the same building as the harbour bistro Valimo. The harbour has electricity for charging, drinking water, laundry facilities, waste disposal and septic tank emptying, among other things, but some services may only be available on some days of the week, so check the services, their availability and the harbour fees on the guest harbour's own website. Note that the adjacent dry dock is a work site, and access to it is prohibited for safety reasons.

Day visits, fees and services

All mooring in the guest harbour is subject to a fee, including a short day visit. Check the up-to-date prices and instructions on the guest harbour's website. Berths cannot be booked in advance.

In the summer season, all of Suomenlinna's restaurants, cafés and bars are open, and many also serve visitors in the winter season. There are several public toilets on the island. The Suomenlinna Visitor Centre is in the pink Jetty Barracks (Rantakasarmi) in front of the main HSL pier.

The Suomenlinna Museum and the Military Museum are open all year round, and the Ehrensvärd Museum, the submarine Vesikko and the Customs Museum in the summer season. Check the opening hours of the museums, cafés and restaurants on the Suomenlinna website before you set off.

Large ships cause strong currents in the Kustaanmiekka strait, and the water can rise quickly and unexpectedly on the shore rocks. If you want to swim, Suomenlinna's swimming beach is between Kustaanmiekka and Susisaari. Open fires and barbecuing, including the use of camping stoves, are prohibited throughout the fortress area.

Getting to Suomenlinna and the guest harbour (opens in a new tab)

Up-to-date information

Accommodation in Suomenlinna

You can stay overnight in Suomenlinna all year round at Hostel Suomenlinna or Villa Silo, and from early summer until well into the autumn a beach cottage can also be booked. If you stay on the island, moor the boat for the night according to the guest harbour's instructions.

Remember before you set off

  • Arrange the boat pick-up and refuelling with the boat's owner.
  • Check the guest harbour fees and the opening hours of the museums and cafés.
  • Good walking shoes for exploring the ramparts and fortifications.
  • Clothing suitable for the weather and something to drink for the journey.

Shall we head out on a boat trip to Suomenlinna?

Rental boats in the Helsinki region are listed on Friilo. Arrange the boat pick-up and refuelling with the boat's owner.

See rental boats on Friilo (opens in a new tab)

See also

Similar destinations by theme: Harbours with saunas · Restaurant harbours · Short boat trips