Hadrian’s Wall also was sited on forbidding geography, making a wall almost beside the point, ideal for a leisure loving queen, er, emperor; image search:
http://www.google.com/search?q=Hadrian%27s+Wall&sa=X&oi=image_result_group&tbm=isch
regarding the Antonine Wall:
The Wall After the Romans
http://www.antoninewall.org/about-wall/wall-after-romans
wiki-waki:
https://en.wikipedia.org/wiki/Antonine_Wall
image search:
http://www.google.com/search?q=Antonine+Wall&ie=UTF-8&tbm=isch&ei=UpCTWvTIKqiatgXH6aPoCA&start=20&sa=N
What got me started on this was some more reading, found another old British earthwork I’d never heard of, Grim’s Ditch, which took its name from one of the names for Odin / Woden. In Scotland (thanks to the colonization of Celtic territories by the Vikings pretty much immediately after the Romans pulled out; the Orkneys were apparently uninhabited prior to the Vikings) the Antonine Wall is also called Grim’s Ditch or Dyke (Deek), despite a different and more recent origin and location.
There was also the WasDyke and Offa’s Dyke in Britain. Post Roman.