|Photo courtesy Jean-Pierre Neri via Wikimedia Commons.|
This is an aerial photo of Lambaesis, a Roman fort in what is now Algeria. It was built during the reign of Emperor Hadrian (117–138 AD). This was a permanent camp for the III Augusta legion complete with fortification walls, baths, an amphitheater, and temples.
Meanwhile, at the empire's northern frontier at the edge of Scotland, Hadrian was building the wall that would bear his name. The below photo is an aerial view of Housesteads fort, situated on the wall and the base for the II Augusta legion. While it's smaller than the contemporary fort in Algeria, you can see that its based on a very similar plan. The Romans standardized many of their buildings, only varying them because of special needs or terrain. Thus if a legionnaire decided to switch from the III to the II legion, and moved from the heat of Algeria to the damp of Scotland, he'd be able to make his way around the fort without any problem.
A few years ago I did a series about hiking Hadrian's Wall on the now-defunct travel blog Gadling. The photo galleries are gone but all my text is still up.
The photo of Housesteads is courtesy the Tynedale U3A. Hadrian's Wall Group, which is doing great work educating the public about Hadrian's Wall.