It is "Enterence E" to the platform to Kőbány-Kispest. The photo was taken on the day the renovated stations opened. Overground, the enterence is at Váci út, in front od Duna Plaza
<a href="//commons.wikimedia.org/w/index.php?title=User:Vauia_Rex&amp;action=edit&amp;redlink=1" class="new" title="User:Vauia Rex (page does not exist)">Vauia Rex</a>
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<span class="int-own-work" lang="en">Own work</span>