27 MAY 2026
Söderarm — nature reserve and lighthouse
Söderarm is Roslagen's most remote and wild outpost towards the open sea. Here in the outer archipelago stands a 21-metre high stone lighthouse from 1839 on the small rocky island of Torskär — one of Stockholm county's most dramatic natural encounters.
The Outermost Point of the Outer Archipelago
Söderarm lies 11 nautical miles from the mainland, north of Kapellskär, out in the middle of the Åland Sea. The island's name Söderarm — like its neighbouring lighthouse Nordkoster to the north — refers to how the island groups stretch out from the mainland like arms towards the open sea. The lighthouse island itself is actually called Torskär.
The Lighthouse — Built in 1839
Söderarm lighthouse was constructed in 1838–1839 and lit for the first time on October 17, 1839. The cylindrical stone tower is 21 metres tall with a characteristic red band in the middle of its whitewashed shaft. The lighthouse served for a long time as an approach lighthouse for shipping lanes to Kapellskär, Norrtälje and Stockholm — together with the sister station Tjärven to the south.
Originally the lighthouse was illuminated with a rotating oil lamp and mirror apparatus. Over the years it was modernised: paraffin lamp in 1882, Dalén light in 1928 and complete electrification in 1953. The lighthouse was staffed until 1997.
Nature and Birdlife
The archipelago surrounding Söderarm is known for exceptional birdlife. White-tailed eagles are seen regularly over the island throughout the year — with wingspans of up to 2.5 metres they are an impressive sight. During spring and autumn large numbers of migratory birds pass through: waxwings, robins, redpolls and lesser spotted woodpeckers stopover on their journey along the Baltic coast.
Getting to Söderarm
Söderarm has no regular scheduled boat service. A water taxi can be ordered from Räfsnäs, the nearest landing harbour on the mainland north of Kapellskär. A private leisure boat is the most common option for visitors. The island group around Söderarm is popular with sailors and sea kayakers.
- Location: 11 nautical miles northeast of Kapellskär, Norrtälje municipality
- Lighthouse: Söderarm lighthouse, lit in 1839
- Tower height: 21 metres
- Birdwatching: White-tailed eagle, migratory birds and seabirds