to get an idea of a Roman Fort that was built on the frontier in Germany, “the Limes” go to: https://en.wikipedia.org/wiki/Saalburg
Saalburg is just north of Frankfurt. And for General Patton fans, he stopped here for a short visit to see the ruins after he left Bad Nauheim on the fatal morning in December, 1945.
Post war excavation and the rebuilding of the fort is shown here. It is a great place to visit if you are in the Frankfurt am Main areal and have a spare afternoon or morning.
Sweet!