Just next to the entrance to Orpington Station there is an archeological site. The remains of a Roman villa were discovered in 1926 and, subsequently, the site was excavated. A building was constructed around the site, to protect it.
(Photo by Ian Capper)
This painting (by Wendy Williams) gives an idea of how the villa might have looked in the 3rd century A.D. Presumably, the road (river?) we see at the bottom of the hill is where the High St. now is.