Nammer Lager, Archaeological site in Porta Westfalica, Germany.

Nammer Lager is a hillfort on the western end of the Wesergebirge above Nammen, a district of Porta Westfalica. Its 25-hectare interior slopes north; a double rampart with an outer ditch bounds it on the north and east, cliffs protect the south, and a single rampart faces the steep Lehmsiek to the west. The only gate lies at the northwest corner, and three spring hollows inside supplied water.

The fortification was built during the Iron Age when people in the region protected their settlements with walls and ramparts. Archaeologists began studying this location in the late 1800s and laid the groundwork for understanding how this ancient structure was used.

The name comes from the village of Nammen below the site. Pottery sherds and the fortification technique found here show clear Celtic La Tène style elements, though whether the builders were Celts or a local population using that style is still unresolved. Iron ore and abundant wood at the Porta Westfalica supported trade in iron goods and salt, making the site an early predecessor of Minden.

The site is accessible via marked hiking trails that allow visitors to explore the various sections of the fortification and learn about its structure. Information boards help guide you through the area and explain different parts of the site.

The fort was part of a network of several ring fortifications in the region that were strategically positioned along ancient trade routes. This connection to other similar sites shows how important this location was within a larger defensive system of ancient times.