Flaten, Nature reserve in Stockholm, Sweden

Flaten is a nature reserve in Stockholm that encompasses woodlands, wetlands, and a lake with exceptionally clean water. The area features marked trails throughout and diverse habitats that support various plant and animal species across different seasons.

The reserve was established in 2007, covering about 736 hectares, of which 547 are land and 189 water, making it Stockholm's largest nature reserve. Its land and water once belonged to the Orhem and Skarpnäck estates, whose fields and pastures shaped the open cultural landscape. Skarpnäcksgrottan, a hillfort and a steep cliff with some of Stockholm's hardest climbing routes, lie within the area.

The reserve serves as a learning space where visitors discover environmental protection through guided tours and information displays. It functions as a place where people of different backgrounds come to understand natural ecosystems firsthand.

The area is easy to navigate with multiple marked trails for hiking, birdwatching, fishing, and canoeing. Conditions vary by season, so it helps to plan your visit based on what activities interest you most.

The reserve's wetland at the lake's north-western end holds a beaver colony, and Skarpnäcksgrottan, a hillfort with a very steep cliff, carries some of Stockholm's hardest climbing routes. The old road to Tyresö now runs through as a foot and cycle path between Flatenvägen and Flatenbadet.