top of page

Bunker sauna

atmospheric sauna in the historical and scenic Kuninkaansaari Island of Helsinki


Kuninkaansaari island's wood-heated sauna - also known as "The Box" - is located next to Sand Cove, near the old Officer's House. The concrete bunker has been used as a sauna at least since the early 1940s. The sauna has been used primarily by the island's military personnel and their families. Now, our customers also have the opportunity to enjoy the rugged but charming Kuninkaansaari Sauna.


If you are looking for a modern, freshly painted, decorated and up-to-date urban sauna, you are probably in the wrong place. You can hardly find a straight or flat surface from the Kuninkaansaari Sauna, but a scuffed space with a special personality. Its long life and history can be seen in the jagged surfaces of the walls, the warm twilight of the changing room, the surrounding nature and the smooth cliffs with their old writings.


With the exception of some necessary renovations, the sauna has been kept as it has been for decades. The bumps and the crooked roof are the essence of The Box. This sauna is for those who do not care about the occasional leafs in the water of the well and who enjoy the atmosphere of the wood-heated sauna and the amazing soft steam without any additional disturbance.


The Sand Cove's cliffs are 50 metres away from the sauna and it is also possible to swim there. The sandy beach is around 100 metres from the sauna.

"Aivan mielettömän ihana symppis Koppi-sauna!"


Prices in 2024 (including VAT)

In 2024, the sauna can be reserved for Transformer accommodation customers in connection with the accommodation. The day sauna can only be reserved on Sundays (Boater's Sunday sauna on Sundays from 1 pm to 4 pm and 5 pm to 8 pm). The sauna is booked from the booking calendar of the online store. The price for transformer accommodation customers is €90 and €115 for day sauna customers.

Good to know

  • You will receive written instructions in your email regarding your arrival and use of the facilities week before of your stay.

  • The sauna heats up in about an hour, sometimes faster in the summer time.

  • Firewood can be found in the dressing room.

  • We use carried water. The water point can be found along the sauna trail. Do not use seawater at all in the sauna.

  • The sauna can accommodate 5-6 persons at the same time. Facilities are not suitable for large groups.

  • No alcoholic beverages are served on the premises. Bring your own alcoholic beverages and refreshments.

  • Swimming on your own risk at the nearby beach. You can find the rocky beach by following the path leading from the sauna.

  • The sauna has a fridge and an outlet that can be used for charging a phone etc.


You should take with you


  • Towel

  • Swimsuit

  • Beach sandals or other footwear for walking on the path and beach

  • Something to drink

  • Soap / Shampoo (limited amount available at the sauna)

Kannattaa ottaa mukaan

Make a booking


Booking in 2024


For the time being, the sauna can be booked as follows:

  • Accommodation guests, Tuesday to Saturday from 6 pm to 10 pm or from 7 pm to 11 pm.

  • Boater's Sunday sauna on Sundays from 1 pm to 4 pm and 5 pm to 8 pm (the first can also be reached by using water bus, the latter cannot)

Make a booking by going directly to the booking site. Sauna is available from the beginning of May until the end of September. 




Kuninkaansaari Island can be reached via Vallisaari Island with connecting ships. From Vallisaari to Kuninkaansaari, you travel along the embankment. You should reserve time for a walk from Torpedo Bay approx. 15-20 minutes (from Pilot Yard approx. 25-30 minutes). You can also come to Vallisaari with your own boat. Kuninkaansaari does not have a berth for your own boat.


Phone +358 (0) 40 764 9766

(Mon-Fri 10am-5pm, Sat-Sun 11am-4pm)

Helsingin Saaristoretket

Business ID: FI27652404

bottom of page