Start: N 59°10.761' E 017°40.010'. Parking at Östertälje station, approx. 800 metres after the section start.
Temporary stretch of the stage in 2018 marked with orange bands / S-stickers and blue-pointed on the map here.
From Östertälje commuter train station, the trail goes towards Södertälje Canal and the docks of Östertälje Boat Club. The trail continues on the walkway along the east side of the canal under several bridges (which can be quite noisy) and past the Sydpoolen water center. The trail then goes due west over Slussbron Bridge and the pedestrian bridge at Lake Maren, and through the City Park, Before turning down into the station area.
After the train station, the trail continues towards Tvetaberg. After passing the Circle K petrol station at road Nyköpingsvägen, the trail turns right and enters a woodland park, and then passes through a small beech forest and the Saltskog housing estate. The trail continues under a local street and the motorway past Scania's gearbox factory, and onwards over the Tvetavägen road and through a wooded area, passing the Hovsjö housing estate.
When the landscape opens up, the trail passes Eklundsfältet allotment gardens to reach the beach at Eklundsnäsbadet. At the parking area, the trail turns left and follows the south-east shore of Lake Måsnaren to the end of the section at Tveta, at a sports club belonging to the Södertälje-Nykvarn orienteering club.
Along the shore of Lake Måsnaren, Sörmlandsleden overlaps with the Måsnarenleden trail, marked in blue. This trail of around 12 km circles Lake Måsnaren. A short section of Måsnarenleden in turn overlaps with Täljeleden along the north-east shore of the lake. Täljeleden has yellow markings and is approx. 23 km long. It passes through the Bårsjön nature reserve.