Does the map have to reflect the town as it is today or can it be contemporary with the historical portion that is being emphasised?

For example in my town there's evidence of Iron Age settlements, Anglo-Saxon settlements, there's ruins of a 12th century priory, and the 7th century school where Thomas Paine was educated still exists today. Do I imagine the way things looked in one of those time periods or do I emphasise the location of one (or more) of them on a modern map of the area?