Switzerland hasn't been engaged in a military conflict for over 150 years, but hidden beneath the country's surface is a vast network of military bunkers and fallout shelters that exist to protect the Swiss people from potential onset of war and nuclear devastation. Many of these were built during the Cold War, when the threat of nuclear bombs seemed very real indeed.
Although the exact number of military bunkers isn't known, a common estimate is that there are around 20,000 bunkers dotted around Switzerland. There are also more than 300,000 private and public fallout shelters around the country.
All of which means that Switzerland would appear to have some potential protection for its citizens if nuclear conflict did occur, although it's not known just how effective these shelters – some built many decades ago – would be against modern-day threats.
But that doesn't stop us from taking a look into some of these mysterious spaces, thanks to a photographer calling himself Kecko, who's chronicled some of the most interesting bunkers and shelters in Switzerland. Here are a few of our favourites.