Seesperre Nas

Seesperre Nas is a fortified defense system on Lake Lucerne positioned between Nidwalden and Lucerne cantons. It comprises two artillery installations called Ober Nas and Unter Nas, strategically placed at the narrow passage of the lake.

The fortification was built in 1940 as part of Switzerland's defense strategy during the Second World War. It protected the entrance to the national redoubt, the core of Swiss territorial defense at that time.

The Nidwalden Museum displays the history of this naval defense through exhibitions featuring artifacts, documents, and photographs from the Second World War era. Visitors can see how the fortification was integrated into the daily military life of the region.

Access to the site and information about tours is available through the Nidwalden Museum website, which manages the historical fortification. The museum offers visitors regular opportunities to explore this defensive installation.

The defense system included a floating barrier approximately 410 meters long made of barbed wire and concrete blocks. This water defense was unique in Switzerland and had no similar counterpart elsewhere in Europe.

Location: Lucerne

Location: Nidwalden

Location: Schwyz

GPS coordinates: 46.99722,8.46739

Latest update: December 9, 2025 12:20