years ago, we visited https://www.nationaltrust.org.uk/visit/gloucestershire-cotswolds/chedworth-roman-villa a Roman villa in England. The surviving tile mosaics were quite fascinating. We also stopped at Hadrian's Wall, of which there's very little left. I imagine there are remnants of Rome across much of the continent and some areas beyond. Perhaps in a few thousand years they will be saying the same of the old USA outposts around the world.