Old maps often contain clues which help digging archaeologists understand features that they find below ground. The maps also contain a wealth of information for landscape archaeologists, as they show how the landscape has changed over the years. Some 30 historic maps of Chester have been identified so far, the earliest dating from around 1580, and these will be carefully analysed to see if they contain clues to help understand how the amphitheatre may have influenced the development of the landscape of Chester .
A cartographer by the name of John Speed produced a map of Chester in 1610, and it is particularly interesting as it shows that the northern curve of the amphitheatre survived as a visible feature in Chester at that date.
This curve suggests that the outer wall of the amphitheatre (or at least another wall built on the same line) and the road on the outside of it, had continued to be visible in the landscape since the Roman period. The fact that the curved route of Little St John Street, which you can still see today, can traced on all maps from that date, is a good example of how cartography can reveal early features which were sufficiently important enough to be retained as boundaries or routes around which the later urban landscape developed.
[Above] The 1610 John Speed map, with the Amphitheatre area highlighted and magnified - © Cheshire Record Office.
As well as being used to analyse how the landscape of Chester has evolved, the maps are being used on a day to day basis to help the excavation team identify features they unearth. For example, the corner of a brick floor was found by the excavators in Area A. The team took accurate measurements to this feature, and then plotted them on the detailed topographic survey. They then compared the results with previous maps and surveys of the site which had been scanned into computer mapping software. This allowed the team to positively identify this feature as a floor within a building shown on the 1875 1:500 scale Ordnance Survey map. Similarly, features which showed up on the geophysical survey can be identified on previous maps.
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