There's a brilliant post over on the Eurobricks forum that tells the history of Hadrian's Wall (part of which I walked on many years ago) and illustrates it with a LEGO build of one of the milecastles that the Romans set up along the length of the wall.
It's a great build that is wonderfully photographed, plus free bonus history. Well worth your time.
Source: EuroBricks: Hadrian's Wall
LEGO Castles — Hadrian's Wall by Eoghann Irving, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.