The Brohltalbahn Mallet locomotive, built in 1906 by the Humboldt Engine Factory in Cologne-Kalk, No. 348. Withdrawn from service on 29 January 1966, and restored from November 2008 to February 2015.
<a href="//commons.wikimedia.org/wiki/User:Spurzem" title="User:Spurzem">Lothar Spurzem</a>
CC BY-SA 2.0 de
<span class="int-own-work" lang="en">Own work</span>