Lange Dammwiesen und Unteres Annatal, nature reserve in Brandenburg, Germany

Lange Dammwiesen und Unteres Annatal is a 1.26-hectare nature reserve in Brandenburg, managed by the NABU regional association Strausberg-Märkische Schweiz. It lies on the Ostbrandenburgische Platte, a section of young moraine land shaped during the Weichselian glaciation. Its geological feature is the Oser, gravel ridges that gave the area its name "long dams".

The area was shaped thousands of years ago by glacial processes that created the ridge formations. In the 20th century it experienced intensive use for railway construction and sand extraction before being placed under protection, allowing nature to gradually recover.

The name comes from the osar, long gravel ridges left by the Weichselian ice age, which the locals called "long dams". In times of war, villagers from Strausberg hid in the lowland then known as the "Hennickendorfer Winkel". Today Heck cattle graze the meadows, and their grazing spreads seeds and keeps the grassland open.

Paths through the area are easy to walk and allow stops at water spots for wildlife observation. The terrain is flat to gently rolling, making it suitable for various fitness levels, though wet areas can become slippery after rain.

Rare plants like orchids that were long thought extinct have reappeared in the area after decades of protection measures. This shows how degraded habitats can regenerate when human disturbance decreases and local conservation groups work actively to support recovery.