Aerial photograph of Kruibeke fortress, Belgium; part of the inner ring of military fortifications around Antwerp called the Brialmont belt and built in the 1860s. Despite the name it is currently situated in the municipality of Zwijndrecht. Nikon D60 f=55mm f/5 at 1/4000s ISO 800. Processed using Nikon NX Studio 1.3.2 and GIMP 2.10.34.
<a href="//commons.wikimedia.org/wiki/User:Lieven_Smits" title="User:Lieven Smits">Lieven Smits</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>