Rails, each one bar-coded, stacked for streetcar line construction in <a href="https://en.wikipedia.org/wiki/Vitoria-Gasteiz" class="extiw" title="en:Vitoria-Gasteiz">Vitoria-Gasteiz</a>
<a href="//commons.wikimedia.org/wiki/User:Vmenkov" title="User:Vmenkov">User:Vmenkov</a>
CC BY-SA 3.0
<span class="int-own-work">Self-photographed</span>