When many people think of a vacation to Switzerland, they envision miles and miles of open countryside. In addition to snowboarding, skiing, hiking, zip-line and other open-air activities, there are other kinds of unique Swiss experiences. However, instead of resting in the open air, the Hotel La Claustra resides far underground. The Claustra was originally a secret army fortress, but now the hotel welcomes guests from May through October. In addition to exploring the mountains during the day, the adventurer can enjoy a truly survivalist experience by hunkering down in the bunker. The hotel also has underground scuba tours for the truly adventurous.