The formerly top-secret bunkers at Faulensee were built to house troops defending Thun, Spiez and the Lötschberg railway. During summer, they’re open to the public once a month. Cleverly disguised as farmhouses, the entrances to the bunkers are guarded by cannons and connected by underground tunnels in which you’ll find offices, laboratories, kitchens and cramped sleeping quarters. Tours last 1½ to two hours and you’ll need warm clothing and sturdy shoes. To ask about English explanations, call or email ahead.
Faulensee can be reached by bus from Spiez train station and from Interlaken West by boat (one way/return Sfr12.80/21.60).