Södertörn [sødəˈʈœːɳ] is an island in Sweden, making up the southern part of Stockholm County province, protruding into the Baltic Sea. With many bridges to Stockholm's islands and to Södertälje, Södertörn is usually perceived as part of mainland Sweden.
Northern Södertörn is a part of Stockholm municipality called Söderort. This article covers mainland Södertörn except Stockholm municipality, namely Botkyrka, Haninge, Huddinge, Nynäshamn, Salem and Tyresö. North-eastern Södertörn is part of another municipality called Nacka, which is described in our guide to the Stockholm archipelago. The municipality of Södertälje, to the west of Södertörn, has its own article on Wikivoyage.
The land is mostly rural, untouched by the expansion of Stockholm, except suburbs built along the railways to Södertälje and Nynäshamn, two important industrial ports.
- Nynäshamn, a port town with the ferry to Gotland
- Huddinge with Flemingsberg as the major centre
By public transportation
All built-up areas in Södertörn are served by SL, Stockholm's public transport company. See Stockholm County#Public transit. It is possible to take a bicycle to the train free of charge. Bikes are not allowed in the trains during rush-hours (06:00-09:00 and 15:00-18:00) between Stockholm and Västerhaninge. This is important if you have to catch a ferry in Nynäshamn that leaves in the early evening hours. Choose the first part of the train, because the second often goes only to Västerhaninge.
Some national trains call at Flemingsberg.
- Litografiska museet. In Huddinge displays litographic printing.
- [dead link] Tumba Papermill Museum. The paper mill in Tumba has a 250-year history of making Swedish banknotes. The exhibitions tell the story of the Bank of Sweden, the world's first central bank, and the first one to issue paper money.
- Tyresö slott
- Flottsbrobacken in Huddinge, alpine skiing.
- Tyresta National Park. 20 km south-east of central Stockholm. A part of the park was devastated by a wildfire in 1999. The park management lets it recover naturally.
- Bornsjön— For a real wild animal safari close to Stockholm, Bornsjön is the best spot. It is a nature reserve 30 minutes drive south of Stockholm. The natural environment is perfect here for watching mammals like moose, roe deer and wild boar. Stockholm Outback offers tours down to the reserve every evening during the summer. For further information call +46 73-6578708 or visit their homepage .
- Haninge Centrum, the dominant shopping mall of Södertörn.
As in the rest of Sweden, most suburban centres contain pizza and kebab restaurants.
Except Stockholm, nightlife in Södertörn is concentrated to Södertälje, Haninge, and Nynäshamn.
Nightlife in Nynäshamn peaks at summer.
- [dead link] Nynäs havsbad. A four-star waterfront hotel in Nynäshamn.
- Häringe Palace. A 17th-century manor, with traces of history back to the Middle Ages.
- Södertörn University in Flemingsberg. 
There are two emergency hospitals in the area: Södertälje sjukhus in Södertälje, and Karolinska Institutet Huddinge in Flemingsberg.
- From Nynäshamn ferries go to Gotland, a very popular summer destination and Sweden's largest island.
- Another more off the beaten track-option from Nynäshamn is to take the boat to the beautiful and isolated national park island of Gotska Sandön.