You can easily get to Sysmä or near by areas.
From Lahti you can get to Asikkala and Padasjoki along route 24. You can get to Sysmä either via Asikkala: routes 24 and 314 or via Heinola along routes 4/E75 and 410.
Helsinki – Sysmä 175 km
Helsinki – Hartola 180 km
Lahti – Sysmä: 70 km
Lahti – Hartola: 81 km
South Päijänne can also be reached by bus. There are good bus connections to Lahti, from which there are further connections to Asikkala, Padasjoki or Sysmä.
Bus timetables: Matkahuolto
The nearest train station is located in Lahti. VR operates several trains a day to Lahti from all over Finland. From Russia it’s easies to travel by the Allegro train. The time from Helsinki to Lahti is under an hour at its fastest and from St Petersburg it takes around 2½ hours.
Schedule information: VR
Finnair and other airlines operate daily flights to Helsinki from many European locations. At its shortest, the distance to South Päijänne from Helsinki-Vantaa Airport is a little over 100 km. There is also a bus connection to Lahti from Helsinki-Vantaa Airport roughly once every hour.
Detailed flight schedule information: Finnair
More detailed schedule information from Helsinki-Vantaa Airport to Lahti: Matkahuolto