This was the "Fürsteneingang", a special entrance for the 
Duke of Saxony, in Dresden Hbf. The platform is currently
not in use, the front part of the entrance is used as a
cinema, the rest is probably a storage room. Perhaps it
will be opened again when the station is rebuilt? 
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photo: <a href="mailto:unci@tigerden.com">tobias b köhler</a>