One of the storage buildings (Magasiner) at Kastellet in Copenhagen, Denmark. Something built into one of the ramparts.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/40679698@N00">Frans Drewniak</a> from Copenhagen, Denmark
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/drzimage/4632277350/">Kastellet maj 2010</a>