U-Bahn 3 in subway station "Schweizer Platz",  Frankfurt on the Main (08/2017 - with a ligth camera and good shoes ... :- ) ....)
<a href="//commons.wikimedia.org/wiki/User:GraphyArchy" title="User:GraphyArchy">GraphyArchy</a>
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<span class="int-own-work" lang="en">Own work</span>