The Glecksteinhütte in Fallätsche, Zurich.  This hut was built in the early 1900's for mountaineering in the Fallätsche erosion zone.  Today it is in danger of falling off the cliff and can not be entered safely anymore.
<a href="//commons.wikimedia.org/wiki/User:Domob" title="User:Domob">Daniel Kraft</a>
<span class="int-own-work" lang="en">Own work</span>