Großes Fenn

The Großes Fenn is a peat bog and protected nature reserve within the Düppeler Forst woodland in Berlin's Wannsee district, designated under nature protection law in 1959. Bogs of this type form over millennia through the accumulation of waterlogged peat and support specialist flora including sphagnum mosses, cottongrass, and carnivorous plants. It is one of the few remaining moorland patches within Berlin's city limits and serves as a refuge for rare invertebrates and bird species. Forest trails through the surrounding Düppeler Forst allow walkers to approach the area; the bog itself remains largely off-path to protect its fragile ecosystem, preserving a genuine sense of quiet remoteness.