The muzzle of a 15cm gun is seen in a bunker at the former artillery fort Furggels of the Swiss Army near the village of St. Magrethenberg, Switzerland January 6, 2016. Artillery fort Furggels was in military use from 1946 to 1998 and is now open to the public as a museum. With the threat of foreign invasion a thing of the past, thousands of military bunkers and fortresses in Switzerland have been put to commercial use, from hotels to data centres, museums to cheese factories. The Swiss army has sold most of these decommissioned strongholds, but about a thousand unused bunkers remain, many still disguised as houses and barns. REUTERS/Arnd Wiegmann PICTURE 27 OF 27 - SEARCH "SWISS BUNKER" FOR ALL IMAGES