<a href="https://en.wikipedia.org/wiki/U-Bahn_Frankfurt" class="extiw" title="en:U-Bahn Frankfurt">Frankfurt Subway</a> basic routes.
<a href="https://de.wikipedia.org/wiki/User:Chumwa" class="extiw" title="de:User:Chumwa">Maximilian Dörrbecker</a> (<a href="https://de.wikipedia.org/wiki/User:Chumwa" class="extiw" title="de:User:Chumwa">Chumwa</a>)
CC BY-SA 2.5
<span class="int-own-work" lang="en">Own work</span>, using <a href="//commons.wikimedia.org/wiki/File:Karte_U-Bahn_Frankfurt.png" title="File:Karte U-Bahn Frankfurt.png">this file</a> by <a href="//commons.wikimedia.org/wiki/User:NordNordWest" title="User:NordNordWest">NordNordWest</a> as background