An old building reflected on a modern building in Thessaloniki, Greece. As the walls of the modern building are covered with glass, by looking at it, we actually see an image of the old building across the street.
<a href="//commons.wikimedia.org/wiki/User:Annatsach" title="User:Annatsach">Annatsach</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>