Björkö is an island in the outer archipelago of Korpo. Byviken, a harbour located on its southern side, is the most popular natural harbour in the southern Archipelago. Boaters are attracted there by its colourful history.

In the middle of the island, there is a lake – Insjön – whose area is 10.5 ha and its deepest point 17 metres. Since the lake is so deep and only has a small brook for an outlet, the water is changed very slowly. It takes 15 years for the water to be changed, when the average for Finnish lakes is about two years. Because of this it is better not to leave any water damaging substances like shampoo or dish detergent in the lake. Björkö's nature is diverse and beautiful. The island's geology is also highly varied, and can be explored on Björkö's fascinating nature trail.

Two people walk on a bare cliff. To the left is the sea, to the right is the lake.

Directions and Maps

  • Coordinates Euref-Fin (~ WGS84) lat: 59° 54.5624' lon: 21° 41.4425'  ETRS-TM35FIN: N: 6653227 E: 203262
  • Nautical chart series: D
  • Nautical chart: 715, 24

By Public Transport


The Excursion Harbour

The mouth of the harbour of Byviken is situated on the southwestern side of Björkö.

  • Harbour number: 806
  • Depth: 1,6 - 10,0
  • Anchor, alongside the mooring 
  • Open: south

Other Services

A summery sea landscape. Sparsely vegetated skerries and islets rise from the sea.

112 Emergency Number

If you have an emergency during your trip, such as getting lost, injured or finding a wildfire, call 112. Read more detailed emergency instructions.

Download the 112 Finland application ( to your phone. When an emergency call is made through the 112 Finland application, the emergency centre attendant is automatically informed of the caller's location.

It is recommended to keep the mobile phone warm and to bring extra food and water with you. There are many excursion locations with no mobile coverage and some mobile phones does not work in sub-zero temperatures, that is why it is always a good idea to let someone know about your itinerary and timetable.

Outdoor Etiquette

A cartoon picture of a family walking on a summer path.

1. Respect nature.

2. Mainly use marked trails.

3. Camp only where it is allowed.

4. Light your campfire only where it is allowed.

5. Do not litter.

Read more