Part of section 53, 51, 50:1, 54 and less than 2 km along small gravel road not part of Sörmlandsleden, 10,5 km
Suitable starting point: Karlfors kvarn along coastal road 219.
GPS: N 58°50.787' E 017°22.884'
Here you find a parking area, rest place, and an old wash house. Bus 554 Nyköping - Trosa/Vagnhärad with connection to Södertälje. Bus stop Månbacken, close by.
The route is described clockwise and starts from the parking area with a steep climb on section 53, towards Sandviks badplats. The path continues across sparse forest and easy-to-walk flat rocks. After less than 1 kilometer, the path crosses road 219 and soon thereafter you reach Nyckelby grave field, believed to date back to the 7th century. The grave field contains eight burial mounds, a number of stone circles and a bauta stone (standing stone).
The route then goes along the road Sandviksvägen. “Our” circular route turns off to the right, onto the gravel road towards Fräkentorp. After approx. 600 m, the route takes the right road (by an enclosure) and shortly thereafter crosses road 219 again and continues to Bråfalls såg, a water-powered sawmill. The equipment has been restored, but the mill closed in the 1940s.
From the wind shelter, the route goes to the right onto section 50. After a few hundred metres, there is a dividing point and we turn right onto section 50:1, which goes between bogs to Lake Stora Frillingen. From there, you walk for a few kilometers through the forest until you reach another dividing point at section 54. We turn left, to Lake Björken. On the shore of the lake is a singular rock of primary limestone with many weathered cup marks. The route continues along the shore to the wind shelter, close to a spit of land, with a fireplace and fine rocks for bathing.
From the spit of land, the route continues along the water to a dam in Kvarnbäcken. Cross the stream and turn right on the Mjölnarstigen path along the lush gulley, down to the parking area at Kvarnbäcken/Månbacken. From the parking area, the Mjölnarstigen path continues to the right, across the stream. After approx. 150 m, the path joins Sörmlandsleden (the Månbackestugorna cottages are approx. 100 m to the right). The route continues to the left on Sörmlandsleden/Mjölnarstigen.
You soon come to the Smedstorp cottage ruin, dating back to the early 20th century. The route continues down across a clearing, and then turns right into the forest and along Kvarndammen to Karlfors kvarn. The mill was built in 1829 and belongs to Nynäs Manor. The mill was in use until 1954.