Red square sign. It reads "Zona A". It may be used in articles related to <a href="https://es.wikipedia.org/wiki/Metro_de_Madrid" class="extiw" title="es:Metro de Madrid">Metro de Madrid</a>.
<a href="//commons.wikimedia.org/w/index.php?title=User:FedericoMP&amp;action=edit&amp;redlink=1" class="new" title="User:FedericoMP (page does not exist)">FedericoMP</a>
2008-04-07
<span class="int-own-work" lang="en">Own work</span>