Jämsän sydän logoSynninlukko is a stunning gorge valley between Jämsänkoski and Jämsä, 7 km from the Jämsä city centre as the crow flies. This breathtaking, shady gorge valley is 50 metres wide and 10-20 metres deep, surrounded by sheer rock faces.

The area is protected for its lush, deciduous vegetation. Rare plants, such as the protected drooping woodreed, also grow here. The wet mire areas are spring-fed. On a hot summer day, the air here is cool as the sun’s rays don’t reach the bottom of the gorge. In the spring, the gorge walls are covered by a delicate sheen of ice.

Synninlukko is the source of many local tales and lore. The shady depths of the rocky gorge has always been an excellent hiding place. During the Great Northern War, it was something of a civilian shelter. The gorge was also a popular haunt of hobos. A potable spring flows from the bottom of the gorge. According to one folk tale, the Synninlukko spring is so deep that when a heifer from from the gorge rim into the spring, it later turned up in the Jämsänjoki River. I wilder versions of the tale, it re-appeared all the way over in Päijänne.

In the Häme dialect of Finnish, the word ‘lukko’ means ‘closed gorge’. The Jämsä word for this is ‘rotti’. The name ‘Synninlukko’ is older than the ‘sins’ of the war – it actually refers to a ‘birth’, ‘synnyinlukko’. Presumably, the gorge had been the birthplace of exiles.

It is easy to reach Synninlukko. The road runs almost all the way to the site and there is a parking shoulder on the side of the road. The 1.8 km trail is easy. The trail climbing up from the gorge watershed is more demanding.


Driving directions:

  • Drive Pääskysmäentie from Jämsä to Jämsänkoski (towards North)
  • Turn left to Haaralantie after the Miekkainpetäjä cemetary and then continue straight about 2 kilometers
  • Turn left to Synninlukontie
  • There is a parking area on your right side after 1,4 kilometers where you can leave your car
  • Walking distance to Synninlukko is about 600 meters
  • The distance between the city centre of Jämsä to Synninlukko is around 10 kilometers
  • During the snowy season the road might be ploughed poorly








Address: Synninlukontie 140, 42100 Jämsä


Synninlukko opaste opastaulu metsöpolku-opasteet