|October 13, 2012
||[Oct. 13th, 2012|11:00 am]
Porta Nigra, Germany
Photograph by Robert Clark, National Geographic
This Month in Photo of the Day: National Geographic Magazine Features
The Porta Nigra, or "black gate," still dominates Trier, Germany. A hundred feet tall, it was built in the second century as part of four miles of walls. Trier was a major city in the late Roman Empire, even serving as a regional capital under several emperors.
See more pictures from the September 2012 feature story "Roman Frontiers."
Take a visual tour of Germany »