As part of European Heritage Days, a visit to Switzerland's biggest bunker.
The Swiss prepared for the worst with this Cold War monument. Built in the 1970s as part of the Sonnenberg motorway tunnel near Lucerne, the giant bunker was designed to accommodate 20,000 people. An exercise in 1987 known as Ameise (ant) revealed serious material flaws as well as problems with transport and organisation. In 2000, the site was mothballed, although a few thousand can still find refuge in smaller, improved facilties in an emergency situation. (Pictures: Emanuel Ammon/Auraonline.ch)