a piece of wire of Polish railway <a href="https://en.wikipedia.org/wiki/Overhead_lines#Overhead_catenary" class="extiw" title="en:Overhead lines">overhead catenary</a>
Krzysztof Maria Różański, (<a href="//commons.wikimedia.org/wiki/User:Upior_polnocy" title="User:Upior polnocy">Upior polnocy</a>)
CC BY 2.5
<span class="int-own-work" lang="en">Own work</span>