Nackareservatet, Nature reserve in Stockholm Municipality, Sweden

Nackareservatet covers 855 hectares of land and water, split into a 754-hectare Nacka section and a 101-hectare Stockholm section. It holds seven lakes, including Källtorpssjön and Söderbysjön, plus pine forest, rocky outcrops and wetlands with small brooks. About 30 km of walking trails, two floodlit tracks and three outdoor swimming spots lie within it, along with Hellasgården and Björkhagen's 9-hole golf course.

Nackareservatet's Nacka section largely matches the land of Nacka gård in 1723, and the area supplied water power to Nacka bruk, an ironworks with roots in a hammer forge that Gustav Vasa had built in 1558. Dug canals linked and dammed the lakes to regulate water flow for the works. In 1939 Stockholm city bought a large tract from Nacka, and the reserve was formally created in 2002 after Stockholm's 1993 decision and Nacka's approval in 1999.

The area serves as a meeting place for people seeking outdoor recreation near Stockholm, with forests and lakes drawing visitors year-round. The Hellasgården facility reflects how sports and physical activity have become central to how locals experience this landscape.

Motor vehicles are banned throughout the reserve, but Ältavägen cuts through it, dividing the area into a larger western part and a smaller eastern part. About 30 km of walking trails, two illuminated ski trails and three open-air swimming spots are available. Fishing with a permit is allowed in all lakes.

The reserve's lakes were linked by hand-dug canals to regulate water for Nacka bruk, a hammer forge founded when Gustav Vasa ordered it in 1558. The same channels now let paddlers pass between Dammtorpssjön, Ältasjön and Drevviken, a route walkers never see.