Until the 19th century, Södermalm was mainly a farmland to support Stockholm. As the railway was built in 1860, Södermalm became a working-class district, until gentrification in the late 20th century. Some of the pre-industrial architecture remains above Slussen.
In the 21th century, Södermalm has gained recognition from the Millennium series by Stieg Larsson. The borough has also earned a reputation of "hipness", making Financial Times' top list of destinations for 2014.
Hammarby Sjöstad is formally a part of Södermalm, the only bit not on the main island. Since the late 1990s, it is under construction on the former docks and small industrial estates after extensive cleanup. The Sjöstad ("city on the lake") was planned from the outset to be a model community for sustainable living and design, including many innovative features in its infrastructure and architecture that limit the quarter's impact on the environment and provide for a better life quality.
Nacka is a municipality immediately west of Södermalm proper. Sickla and Henriksdal, the westernmost districts of Nacka, were harbour districts, which have recently been re-developed and integrated into Stockholm's inner city and are covered in this article. The farther removed eastern part of Nacka, including the seaside resort Saltsjöbaden, is covered in our guide to the Stockholm Archipelago.