Does anybody know further examples like this?

[Nathan Ross]

i have found an Area of Minimum 5 roman Fortresses at one place.

Looks like somewhere in the east - Syria or Mesopotamia maybe. Could you tell us the name of the location?

As Robert says, there are a few sites where multiple camps or forts from different eras are overlaid - obviously, armies tended to march along particular routes, and a good camping ground or strategic location would remain the same over the years!

The most obvious example I can think of is Ardoch in north Britain. Here is a schematic of the (probable) dates for the various fortifications. and here's a more detailed plan: