Fort Kugelbake, Military fortification in Döse, Cuxhaven, Germany

Fort Kugelbake is a pentagonal military installation near the mouth of the Elbe River. The structure contains gun emplacements, barracks, and defensive walls arranged to control access to the waterway.

Built between 1869 and 1879, the fort was designed to prevent enemy warships from reaching the Elbe estuary. It survived both world wars and was later protected as a historical monument.

The fort takes its name from the Kugelbake, a wooden sea mark on the Elbe estuary that guided ships; the structure stands just behind the dike near it. The site is now a protected monument, and the blue sign on the concrete front reads "CUXHAVEN".

The fort is easily accessible from central Cuxhaven and has marked pathways throughout the grounds. Visitors can explore on their own or join guided tours to learn more about the military installation.

The moat was not entirely water-filled: the sides facing the sea and the dike were dry trenches backed by a brick loophole wall, while only the flanks and rear held water about two metres deep. The fort also received the world's strongest searchlight in 1909, whose beam reached 4.5 kilometres.