Ahlen-Falkenberger Moor, Halemer/Dahlemer See, Nature reserve and wetland ecosystem in Lower Saxony, Germany

The Ahlen-Falkenberger Moor, Halemer/Dahlemer See is a 40-square-kilometre high moor in the district of Cuxhaven, the largest in the district and among the largest in Lower Saxony. It lies between sandy geest ridges, with the shallow Dahlemer and Halemer lakes covering about 190 hectares, bordered by reed beds and willow scrub. The Dahlemer See has a one-metre steep edge on its eastern shore where it advances into the moor, while its western shore silts up.

Peat cutting by hand began by the 17th century from the moor-edge settlements of Wanna-Süderleda, Ihlienworth-Westerende, Medemstade and Steinau, at only three to five metres a year. Cultivation started during the First World War, using Russian prisoners of war; drainage and fertiliser followed in the 1950s for farmers resettled from Germany's eastern territories. Industrial peat extraction for potting compost began in 1956, and a strip of the Dahlemer See shore was protected as early as 1932.

The name Ahlenmoor combines the villages of Ahlen and Falkenberg with "Moor", the German word for bog. Along the northern and eastern edges, a chain of small peat pits, called Moorkuhlen, marks where farmers cut turf by hand from the 17th century onward, at only three to five metres a year. The cut strips were gradually turned into farmland, and the dried peat was burned as fuel.

The reserve is accessible on foot via marked trails designed to protect the sensitive environment as you walk. Spring and summer offer the best conditions to see wildlife and plants in active growth and movement.

The Dahlemer See shifts with the wind: its eastern bank forms a steep edge about one metre high where the lake pushes into the moor, while the western shore silts up. Boats are banned on both lakes all year, and in winter waterbirds use them as resting grounds.