Roman Heidentor (Heathens Gate) in Carnuntum, Lower Austria.

http://commons.wikimedia.org/wiki/File%3AHeidentor_Carnuntum_4487.jpg

http://upload.wikimedia.org/wikipedia/commons/2/29/Heidentor_Carnuntum_4487.jpg

By Gryffindor (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons