ZURICH• • A hospital, a kitchen, sleeping quarters, a post office and even a graveyard for up to 20 bodies - these were just some of the facilities in a nine-storey fortress used in the 1940s.

"It is almost like a self-contained village," said Mr Werner Heeb, owner of the Tschingel fortress.

On a sheer rock face overlooking a valley of the River Rhine in eastern Switzerland, it once housed 250 men but had beds for only about 80.

"At any one time, a third of the men would be at their posts, another third fixing things and another third sleeping," said the retired Swiss Army colonel. "This system ensured that there were always men on guard. Soldiers had eight-hour shifts so they would not tire out easily."

Like many Swiss forts and bunkers, the Tschingel fortress - with its own cable car for goods transportation - was used for military operations but was never under fire as Hitler did not invade Switzerland. Still, they are a reminder of Swiss military efforts at a vulnerable time.

"I want our children to know what their ancestors have done to keep the freedom of this country," said Mr Heeb, who bought Tschingel fortress in 2005.

With the help of volunteers and donors, the place has been turned into a living history book where private guests can rent special military-themed rooms for seminars or experience a day in the life of a WWII soldier.

Other museums like Sasso San Gottardo on the St Gotthard Pass offer the public and tourists a glimpse into Swiss military history in their forts. On display are old military bunk beds, offices and ammunition.

There are also special exhibitions on mountain crystals and the history of transport around the St Gotthard Pass. Said its sales director Tom Markwalder: "Foreigners might know us for the Swiss army knife. But for Swiss military history, there's nothing quite like visiting forts and bunkers."

Kash Cheong