Festung Heldsberg

Festungsmuseum Heldsberg

Useful Information

Location: Obere Heldsbergstrasse 5, St. Margrethen.
Located in a foothill between St.Margrethen and Au, parking at the train stations St. Margrethen. RTB bus from the train stations St. Margrethen and Heerbrugg to stop Heldsberg.
(47.443470, 9.643530)
Open: APR to OCT Sat 10-16.
Fee: Adults CHF 12, Children (6-16) CHF 6, Children (0-5) free, Audio-Guide CHF 3.
Classification: SubterraneaWorld War II Bunker SubterraneaSecret Bunker
Light: LightIncandescent Electric Light System
Dimension: L=1,000 m.
Guided tours:
Address: Festungsmuseum Heldsberg, Obere Heldsbergstrasse 5, 9430 St.Margrethen, Tel: +41-71-733-4031. E-mail: contact
Postanschrift: Festungsmuseum Heldsberg, 9444 Diepoldsau.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1938 begin of planning.
1939 start of constructions.
1940 completed.


The Festung Heldsberg (Heldsberg fortress) is a defensive fortification at the eastern entrance to Switzerland. Here the wide and flat valley of the Alpenrhein opens to the north, towards Germany and Austria. This is the upper part of the Rhine river, which flows into the Bodensee (Lake Constance). For some kilometers the Swiss border to Austria is formed by the Rhine river, not by a mountain ridge, and so in case of an invasion this would have been the ideal geography to enter the country. A second possibility would have been an attack across Lake Constance, and this fortress also protected this border.

At the beginning of World War II the Swiss government planned various fortifications to protect the borders wherever they are not protected naturally by steep mountains. So this underground fort was planned before the war, after Austria was annexed by Germany on 12-MAR-1938, at this strategic location and built during the early years of the war. The power of the fortress was known to the Germans, so an internal German report called Operation Tannenbaum (operation Christmas tree) contained the recommendation to avoid this area in case of am attack against Switzerland, because of the fortress.

The fortification is a 1,000 m long tunnel which had space for some 200 soldiers. It is protected by four 7.5 cm cannons and seven machine guns. 21 more machine guns were located in satellite bunkers, where 400 more soldiers were stationed. It was also equipped with mine throwers and various anti-tank weapons. The area was covered with barbed wire and anti-tank obstacles.

The bunker is today used as a museum for this kind of fortresses. It shows anti-airplane and anti-tank canons, heavy infantry weapons and ammunition from World War II. There is an exhibition of hand held weapon development in Switzerland during the last century and a collection of ammunition cross-sections. A part of the exhibition shows historic and contemporary communication equipment. And finally there is an exhibition of binoculars, sighting mechanisms, and telescopic sights. There are also lamps, gas masks and other equipment. The exhibitions were donated by locals.

The museum is located at a paved road with restricted access. People with walking disabilities may request a permit to enter the road. Others have to walk about 15 minutes, about 500 m uphill. At the foot of the hill the restaurant Schäfli offered parking some years ago, but unfortunately the lessee changed and the new lessee does not allow parking. Please refrain from parking on this private parking lot, you might get towed. The next public parking is located at the train station in St. Margrethen, from there it's a 2 km/30 minutes walk.